Galaxies are massive collections of stars, gas and dust held together by gravity. There are different types of galaxies including spiral, elliptical and irregular galaxies. Galaxies form from dense fluctuations after the Big Bang and their structure depends on the initial rate of star formation - faster formation leads to elliptical galaxies while slower formation allows gas to collapse into disks forming spiral galaxies. Observations of the rotation curves of galaxies and hot gas show that galaxies contain far more mass than the visible mass accounted for, known as "hidden mass". Dark matter in the form of weakly interacting massive particles is currently the best candidate to explain this missing mass.
Magnetic field, Rotational curve, mass, Luminosity of Milky Way GalaxySiraj Ud Daula Shamim
This power point presentation is helpful for astrophysicist whose are interested about magnetic field,mass,rotational curve and luminosity of our galaxy.In this slide,there are some very interesting graph and a video clip which is helpful for imagination.
We report the discovery of spiral galaxies that are as optically luminous as elliptical brightest cluster
galaxies, with r-band monochromatic luminosity Lr = 8 14L (4:3 7:5 1044 erg s 1). These
super spiral galaxies are also giant and massive, with diameter D = 57 134 kpc and stellar mass
Mstars = 0:3 3:4 1011M. We nd 53 super spirals out of a complete sample of 1616 SDSS
galaxies with redshift z < 0:3 and Lr > 8L. The closest example is found at z = 0:089. We use
existing photometry to estimate their stellar masses and star formation rates (SFRs). The SDSS
and WISE colors are consistent with normal star-forming spirals on the blue sequence. However, the
extreme masses and rapid SFRs of 5 65M yr 1 place super spirals in a sparsely populated region
of parameter space, above the star-forming main sequence of disk galaxies. Super spirals occupy a
diverse range of environments, from isolation to cluster centers. We nd four super spiral galaxy
systems that are late-stage major mergers{a possible clue to their formation. We suggest that super
spirals are a remnant population of unquenched, massive disk galaxies. They may eventually become
massive lenticular galaxies after they are cut o from their gas supply and their disks fade.
Evidence for reflected_lightfrom_the_most_eccentric_exoplanet_knownSérgio Sacani
Planets in highly eccentric orbits form a class of objects not seen within our Solar System. The most extreme case known amongst these objects is the planet orbiting HD 20782, with an orbital period of 597 days and an eccentricity of 0.96. Here we present new data and analysis for this system as part of the Transit Ephemeris Refinement and Monitoring Survey (TERMS). We obtained CHIRON spectra to perform an independent estimation of the fundamental stellar parameters. New radial velocities from AAT and PARAS observations during periastron passage greatly improve our knowledge of the eccentric nature of the orbit. The combined analysis of our Keplerian orbital and Hipparcos astrometry show that the inclination of the planetary orbit is > 1.22◦, ruling out stellar masses for the companion. Our long-term robotic photometry show that the star is extremely stable over long timescales. Photometric monitoring of the star during predicted transit and periastron times using MOST rule out a transit of the planet and reveal evidence of phase variations during periastron. These possible photometric phase variations may be caused by reflected light from the planet’s atmosphere and the dramatic change in star–planet separation surrounding the periastron passage.
Magnetic field, Rotational curve, mass, Luminosity of Milky Way GalaxySiraj Ud Daula Shamim
This power point presentation is helpful for astrophysicist whose are interested about magnetic field,mass,rotational curve and luminosity of our galaxy.In this slide,there are some very interesting graph and a video clip which is helpful for imagination.
We report the discovery of spiral galaxies that are as optically luminous as elliptical brightest cluster
galaxies, with r-band monochromatic luminosity Lr = 8 14L (4:3 7:5 1044 erg s 1). These
super spiral galaxies are also giant and massive, with diameter D = 57 134 kpc and stellar mass
Mstars = 0:3 3:4 1011M. We nd 53 super spirals out of a complete sample of 1616 SDSS
galaxies with redshift z < 0:3 and Lr > 8L. The closest example is found at z = 0:089. We use
existing photometry to estimate their stellar masses and star formation rates (SFRs). The SDSS
and WISE colors are consistent with normal star-forming spirals on the blue sequence. However, the
extreme masses and rapid SFRs of 5 65M yr 1 place super spirals in a sparsely populated region
of parameter space, above the star-forming main sequence of disk galaxies. Super spirals occupy a
diverse range of environments, from isolation to cluster centers. We nd four super spiral galaxy
systems that are late-stage major mergers{a possible clue to their formation. We suggest that super
spirals are a remnant population of unquenched, massive disk galaxies. They may eventually become
massive lenticular galaxies after they are cut o from their gas supply and their disks fade.
Evidence for reflected_lightfrom_the_most_eccentric_exoplanet_knownSérgio Sacani
Planets in highly eccentric orbits form a class of objects not seen within our Solar System. The most extreme case known amongst these objects is the planet orbiting HD 20782, with an orbital period of 597 days and an eccentricity of 0.96. Here we present new data and analysis for this system as part of the Transit Ephemeris Refinement and Monitoring Survey (TERMS). We obtained CHIRON spectra to perform an independent estimation of the fundamental stellar parameters. New radial velocities from AAT and PARAS observations during periastron passage greatly improve our knowledge of the eccentric nature of the orbit. The combined analysis of our Keplerian orbital and Hipparcos astrometry show that the inclination of the planetary orbit is > 1.22◦, ruling out stellar masses for the companion. Our long-term robotic photometry show that the star is extremely stable over long timescales. Photometric monitoring of the star during predicted transit and periastron times using MOST rule out a transit of the planet and reveal evidence of phase variations during periastron. These possible photometric phase variations may be caused by reflected light from the planet’s atmosphere and the dramatic change in star–planet separation surrounding the periastron passage.
We discovered two transient events in the Kepler eld with light curves that strongly suggest they
are type II-P supernovae. Using the fast cadence of the Kepler observations we precisely estimate
the rise time to maximum for KSN2011a and KSN2011d as 10.50:4 and 13.30:4 rest-frame days
respectively. Based on ts to idealized analytic models, we nd the progenitor radius of KSN2011a
(28020 R) to be signicantly smaller than that for KSN2011d (49020 R) but both have similar
explosion energies of 2.00:3 1051 erg.
The rising light curve of KSN2011d is an excellent match to that predicted by simple models of
exploding red supergiants (RSG). However, the early rise of KSN2011a is faster than the models
predict possibly due to the supernova shockwave moving into pre-existing wind or mass-loss from the
RSG. A mass loss rate of 10 4 M yr 1 from the RSG can explain the fast rise without impacting
the optical
ux at maximum light or the shape of the post-maximum light curve.
No shock breakout emission is seen in KSN2011a, but this is likely due to the circumstellar inter-
action suspected in the fast rising light curve. The early light curve of KSN2011d does show excess
emission consistent with model predictions of a shock breakout. This is the rst optical detection of
a shock breakout from a type II-P supernova.
Evidence for a_distant_giant_planet_in_the_solar_systemSérgio Sacani
A descoberta de um novo planeta, atualmente não é uma manchete que chama tanto assim a atenção das pessoas. Muito disso, graças ao Telescópio Espacial Kepler, que já descobriu quase 2000 exoplanetas e todo instante uma nova descoberta é anunciada, certo? Mais ou menos, a descoberta anunciada hoje, dia 20 de Janeiro de 2016, é um pouco diferente, pois não se trata de um exoplaneta, e sim de um novo planeta no Sistema Solar, e esse é um fato que intriga os astrônomos a muitos e muitos anos.
Porém, temos que ir com calma com esses anúncios. No artigo aceito para publicação no The Astronomical Journal (artigo no final do post), os autores, Mike Brown e Konstantin Batygin, do Instituto de Tecnologia da Califórnia, apresentaram o que eles dizem ser evidências circunstâncias fortes para a existência de um grande planeta ainda não descoberto, talvez, com uma massa 10 vezes a massa da Terra, orbitando os confins do nosso Sistema Solar, muito além da órbita de Plutão. Os cientistas inferiram sua presença, por meio de anomalias encontradas nas órbitas de seis objetos do chamado Cinturão de Kuiper.
O objeto, que os pesquisadores estão chamando de Planeta Nove, não chega muito perto do Sol, no ponto mais próximo da sua órbita ele fica a 30.5 bilhões de quilômetros, ou seja, cinco vezes a distância entre o Sol e Plutão. Apesar do seu grande tamanho, ele é muito apagado, e por isso ninguém até o momento conseguiu observá-lo.
Não existe ainda uma confirmação observacional da descoberta, mas as evidências são tão fortes que fizeram com que outros especialistas como Chad Trujilo do Observatório Gemini no Havaí e David Nesvorny, do Southwest Research Institute em Boulder no Colorado, ficassem impressionados e bem convencidos de que deve mesmo haver um grande planeta nas fronteiras da nossa vizinhança cósmica.
A talk I gave on Secular (Slow) Processes and Galaxy Evolution given at the Evolutionary Paths in Galaxy Evolution (or "Galaxy Zoo") conference held in Sydney, Sept 2013. (http://www.atnf.csiro.au/research/conferences/2013/gzo/)
Periodic mass extinctions_and_the_planet_x_model_reconsideredSérgio Sacani
The 27 Myr periodicity in the fossil extinction record has been con-
firmed in modern data bases dating back 500 Myr, which is twice the time
interval of the original analysis from thirty years ago. The surprising regularity
of this period has been used to reject the Nemesis model. A second
model based on the sun’s vertical galactic oscillations has been challenged
on the basis of an inconsistency in period and phasing. The third astronomical
model originally proposed to explain the periodicity is the Planet
X model in which the period is associated with the perihelion precession
of the inclined orbit of a trans-Neptunian planet. Recently, and unrelated
to mass extinctions, a trans-Neptunian super-Earth planet has been proposed
to explain the observation that the inner Oort cloud objects Sedna
and 2012VP113 have perihelia that lie near the ecliptic plane. In this
Letter we reconsider the Planet X model in light of the confluence of the
modern palaeontological and outer solar system dynamical evidence.
Key Words: astrobiology - planets and satellites - Kuiper belt:
general - comets: general
The characterization of_the_gamma_ray_signal_from_the_central_milk_way_a_comp...Sérgio Sacani
Past studies have identified a spatially extended excess of ∼1-3 GeV gamma rays from the region
surrounding the Galactic Center, consistent with the emission expected from annihilating dark
matter. We revisit and scrutinize this signal with the intention of further constraining its characteristics
and origin. By applying cuts to the Fermi event parameter CTBCORE, we suppress the tails
of the point spread function and generate high resolution gamma-ray maps, enabling us to more
easily separate the various gamma-ray components. Within these maps, we find the GeV excess
to be robust and highly statistically significant, with a spectrum, angular distribution, and overall
normalization that is in good agreement with that predicted by simple annihilating dark matter
models. For example, the signal is very well fit by a 36-51 GeV dark matter particle annihilating to
b
¯b with an annihilation cross section of σv = (1−3)×10−26 cm3
/s (normalized to a local dark matter
density of 0.4 GeV/cm3
). Furthermore, we confirm that the angular distribution of the excess is
approximately spherically symmetric and centered around the dynamical center of the Milky Way
(within ∼0.05◦
of Sgr A∗
), showing no sign of elongation along the Galactic Plane. The signal is
observed to extend to at least ' 10◦
from the Galactic Center, disfavoring the possibility that this
emission originates from millisecond pulsars.
We present long-baseline Atacama Large Millimeter/submillimeter Array (ALMA) observations of
the 870 m continuum emission from the nearest gas-rich protoplanetary disk, around TW Hya, that
trace millimeter-sized particles down to spatial scales as small as 1 AU (20 mas). These data reveal
a series of concentric ring-shaped substructures in the form of bright zones and narrow dark annuli
(1{6AU) with modest contrasts (5{30%). We associate these features with concentrations of solids
that have had their inward radial drift slowed or stopped, presumably at local gas pressure maxima.
No signicant non-axisymmetric structures are detected. Some of the observed features occur near
temperatures that may be associated with the condensation fronts of major volatile species, but the
relatively small brightness contrasts may also be a consequence of magnetized disk evolution (the
so-called zonal
ows). Other features, particularly a narrow dark annulus located only 1 AU from the
star, could indicate interactions between the disk and young planets. These data signal that ordered
substructures on AU scales can be common, fundamental factors in disk evolution, and that high
resolution microwave imaging can help characterize them during the epoch of planet formation.
Keywords: protoplanetary disks | planet-disk interactions | stars: individual (TW Hydrae)
this power point presentation contain all the description about milky way galaxy & solar system with picture & sound...
by just clicking F11 this PPT will start...
We discovered two transient events in the Kepler eld with light curves that strongly suggest they
are type II-P supernovae. Using the fast cadence of the Kepler observations we precisely estimate
the rise time to maximum for KSN2011a and KSN2011d as 10.50:4 and 13.30:4 rest-frame days
respectively. Based on ts to idealized analytic models, we nd the progenitor radius of KSN2011a
(28020 R) to be signicantly smaller than that for KSN2011d (49020 R) but both have similar
explosion energies of 2.00:3 1051 erg.
The rising light curve of KSN2011d is an excellent match to that predicted by simple models of
exploding red supergiants (RSG). However, the early rise of KSN2011a is faster than the models
predict possibly due to the supernova shockwave moving into pre-existing wind or mass-loss from the
RSG. A mass loss rate of 10 4 M yr 1 from the RSG can explain the fast rise without impacting
the optical
ux at maximum light or the shape of the post-maximum light curve.
No shock breakout emission is seen in KSN2011a, but this is likely due to the circumstellar inter-
action suspected in the fast rising light curve. The early light curve of KSN2011d does show excess
emission consistent with model predictions of a shock breakout. This is the rst optical detection of
a shock breakout from a type II-P supernova.
Evidence for a_distant_giant_planet_in_the_solar_systemSérgio Sacani
A descoberta de um novo planeta, atualmente não é uma manchete que chama tanto assim a atenção das pessoas. Muito disso, graças ao Telescópio Espacial Kepler, que já descobriu quase 2000 exoplanetas e todo instante uma nova descoberta é anunciada, certo? Mais ou menos, a descoberta anunciada hoje, dia 20 de Janeiro de 2016, é um pouco diferente, pois não se trata de um exoplaneta, e sim de um novo planeta no Sistema Solar, e esse é um fato que intriga os astrônomos a muitos e muitos anos.
Porém, temos que ir com calma com esses anúncios. No artigo aceito para publicação no The Astronomical Journal (artigo no final do post), os autores, Mike Brown e Konstantin Batygin, do Instituto de Tecnologia da Califórnia, apresentaram o que eles dizem ser evidências circunstâncias fortes para a existência de um grande planeta ainda não descoberto, talvez, com uma massa 10 vezes a massa da Terra, orbitando os confins do nosso Sistema Solar, muito além da órbita de Plutão. Os cientistas inferiram sua presença, por meio de anomalias encontradas nas órbitas de seis objetos do chamado Cinturão de Kuiper.
O objeto, que os pesquisadores estão chamando de Planeta Nove, não chega muito perto do Sol, no ponto mais próximo da sua órbita ele fica a 30.5 bilhões de quilômetros, ou seja, cinco vezes a distância entre o Sol e Plutão. Apesar do seu grande tamanho, ele é muito apagado, e por isso ninguém até o momento conseguiu observá-lo.
Não existe ainda uma confirmação observacional da descoberta, mas as evidências são tão fortes que fizeram com que outros especialistas como Chad Trujilo do Observatório Gemini no Havaí e David Nesvorny, do Southwest Research Institute em Boulder no Colorado, ficassem impressionados e bem convencidos de que deve mesmo haver um grande planeta nas fronteiras da nossa vizinhança cósmica.
A talk I gave on Secular (Slow) Processes and Galaxy Evolution given at the Evolutionary Paths in Galaxy Evolution (or "Galaxy Zoo") conference held in Sydney, Sept 2013. (http://www.atnf.csiro.au/research/conferences/2013/gzo/)
Periodic mass extinctions_and_the_planet_x_model_reconsideredSérgio Sacani
The 27 Myr periodicity in the fossil extinction record has been con-
firmed in modern data bases dating back 500 Myr, which is twice the time
interval of the original analysis from thirty years ago. The surprising regularity
of this period has been used to reject the Nemesis model. A second
model based on the sun’s vertical galactic oscillations has been challenged
on the basis of an inconsistency in period and phasing. The third astronomical
model originally proposed to explain the periodicity is the Planet
X model in which the period is associated with the perihelion precession
of the inclined orbit of a trans-Neptunian planet. Recently, and unrelated
to mass extinctions, a trans-Neptunian super-Earth planet has been proposed
to explain the observation that the inner Oort cloud objects Sedna
and 2012VP113 have perihelia that lie near the ecliptic plane. In this
Letter we reconsider the Planet X model in light of the confluence of the
modern palaeontological and outer solar system dynamical evidence.
Key Words: astrobiology - planets and satellites - Kuiper belt:
general - comets: general
The characterization of_the_gamma_ray_signal_from_the_central_milk_way_a_comp...Sérgio Sacani
Past studies have identified a spatially extended excess of ∼1-3 GeV gamma rays from the region
surrounding the Galactic Center, consistent with the emission expected from annihilating dark
matter. We revisit and scrutinize this signal with the intention of further constraining its characteristics
and origin. By applying cuts to the Fermi event parameter CTBCORE, we suppress the tails
of the point spread function and generate high resolution gamma-ray maps, enabling us to more
easily separate the various gamma-ray components. Within these maps, we find the GeV excess
to be robust and highly statistically significant, with a spectrum, angular distribution, and overall
normalization that is in good agreement with that predicted by simple annihilating dark matter
models. For example, the signal is very well fit by a 36-51 GeV dark matter particle annihilating to
b
¯b with an annihilation cross section of σv = (1−3)×10−26 cm3
/s (normalized to a local dark matter
density of 0.4 GeV/cm3
). Furthermore, we confirm that the angular distribution of the excess is
approximately spherically symmetric and centered around the dynamical center of the Milky Way
(within ∼0.05◦
of Sgr A∗
), showing no sign of elongation along the Galactic Plane. The signal is
observed to extend to at least ' 10◦
from the Galactic Center, disfavoring the possibility that this
emission originates from millisecond pulsars.
We present long-baseline Atacama Large Millimeter/submillimeter Array (ALMA) observations of
the 870 m continuum emission from the nearest gas-rich protoplanetary disk, around TW Hya, that
trace millimeter-sized particles down to spatial scales as small as 1 AU (20 mas). These data reveal
a series of concentric ring-shaped substructures in the form of bright zones and narrow dark annuli
(1{6AU) with modest contrasts (5{30%). We associate these features with concentrations of solids
that have had their inward radial drift slowed or stopped, presumably at local gas pressure maxima.
No signicant non-axisymmetric structures are detected. Some of the observed features occur near
temperatures that may be associated with the condensation fronts of major volatile species, but the
relatively small brightness contrasts may also be a consequence of magnetized disk evolution (the
so-called zonal
ows). Other features, particularly a narrow dark annulus located only 1 AU from the
star, could indicate interactions between the disk and young planets. These data signal that ordered
substructures on AU scales can be common, fundamental factors in disk evolution, and that high
resolution microwave imaging can help characterize them during the epoch of planet formation.
Keywords: protoplanetary disks | planet-disk interactions | stars: individual (TW Hydrae)
this power point presentation contain all the description about milky way galaxy & solar system with picture & sound...
by just clicking F11 this PPT will start...
That's my lesson plan about earth layers... hopefully it can help you to find your idea...
Don't use the assessment form because it's not really effective to assess your teaching and your student ability... :D
Astronomy - State of the Art - GalaxiesChris Impey
Astronomy - State of the Art is a course covering the hottest topics in astronomy. In this section, the properties of galaxies are discussed, including supermassive black holes and dark matter.
A lecture I'd given on spiral galaxies, barred spirals, mass of galaxies, Sgr A, Elliptical galaxies, standard candles, dark matter, composition of the universe, back in my university days.
You probably need to download the file for the animations to work.
This slideshow explains how scientists measured the size of the universe and its age, It is a miracle that this can even possible to do. The slide show also explain the discovery of the Redshift and the expanding universe. The evolution, the history and the major structure of our universe. It is only within our lifetime, these sorts of question about our origin was asked.
Materials RequiredComputer and internet accessCalcula.docxwkyra78
Materials Required:
Computer and internet access
Calculator
Ruler
Pencils and pens, eraser
Digital camera and/or scanner
Print out
Galaxy Image
Prints document
Total Time Required:
Approximately 2-3 Hours
Part 1. The Local Group
In Table 1, you will find a list of most of the galaxies in the Local Group. This group is made up of our own galaxy, the Milky Way, and its closest neighbors. (Note: 1 kpc = 1 kiloparsec = 1000 parsec; 1 parsec = 3.26 light years)
Table 1. Galaxies of the Local Group
Name
Distance (kpc)
Diameter (kpc)
Name
Distance (kpc)
Diameter (kpc)
Milky Way
-
40.0
IC 1522
610
1.5
Sculptor
60
0.3
WLM
610
2.1
Large Magellanic Cloud (LMC)
60
6.1
Andromeda I
675
0.6
Carina
90
0.2
Andromeda II
675
0.6
Draco
90
0.2
Andromeda III
675
0.9
Ursa Minor
90
0.3
M32
675
1.5
Sextans I
90
0.9
NGC 185
675
1.8
Small Magellanic Cloud (SMC)
90
4.6
NGC 147
675
3.1
Fornax
150
0.9
NGC 205
675
3.1
Leo II
185
0.2
M31 (Andromeda Galaxy)
675
61
Leo I
185
0.3
IC 1613
765
3.7
NGC 6822
520
2.5
M33 (Triangulum Galaxy)
765
14.0
DDO 210
920
1.2
Below is a visual representation of our Local Group of galaxies. You can access and zoom into this image to see galaxies more clearly using this link
Local Group
.
Figure 1.
Local Group Visualization.
Type and label your answers to the below questions in your lab report.
Using Table 1 above and noting the diameters of the galaxies, which
five
galaxies in the Local Group are the largest? In a few sentences, compare the sizes of the other galaxies in the Local Group to the two largest ones.
Which
three
galaxies have the largest angular size (not including the Milky Way)? These galaxies are the ones that look the largest in the sky. Explain how you get your answer.
By hand and with pencil, create a
scale drawing
of the Milky Way and the Large Magellanic Cloud, showing their
relative sizes
and the
distance
between them in kiloparsecs (the galaxies can be represented by circles).
Write down the scale you use ,
and your calculations to find the scaled-down sizes and distance. (An example of a good scale to use would like something like: 5 mm = 10 kpc, also see this site
Basic-Mathematics.com
for more information on scaling.) You will photo your drawing and insert it into your lab report.
Figure 2.
Local Supercluster Print
Image courtesy of Palomar Sky Survey Photographs
As you have already seen, galaxies can vary a lot in size. Now, we will look at how their shapes are different. Two basic types of galaxies are the spiral galaxies and the elliptical galaxies. Spiral galaxies have a disk-like structure,and a central bulge. Our own Milky Way is a spiral galaxy. Elliptical galaxies appear round, looking a lot like a football .
Gravity Gravitation English Presentation
Tugas Fisika
Tugas Bahasa Inggris
oleh :
Kelas 12 IPA 6 SMA Negeri 1 Yogyakarta tahun 2014
Semangat!!!!!!! SUKSES
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
2. What is a Galaxy ? Solar System Distance from Earth to Sun = 93,000,000 miles = 8 light-minutes Size of Solar System = 5.5 light-hours
3. What is a Galaxy? Stellar Region 30 light-years Sun (solar system too small to be seen on this scale)
4. What is a Galaxy? Galaxy 200,000 light-years a massive collection of stars, gas, and dust kept together by gravity Sun’s Stellar Region
5. What is a Galaxy? If our solar system was the size of a cell in the human body, our galaxy would still measure over one mile across.
6. Types of Galaxies Spiral Barred Spiral Elliptical Irregular Peculiar disk-like appearance with arms of stars and dust forming a spiral pattern similar to spirals but with a bright bar of stars and gas through the center elliptically-shaped, with less gas and dust than spirals; no disk or “arms” neither elliptical nor spiral in shape; gas and dust as in spirals but no defined “arms” distorted form of one of the above types, often due to collision with another galaxy or similar catastrophic event
8. Galaxy Formation Galaxies form from the primordial density fluctuations that arise after the big bang and grow under inflation. These density fluctuations form filaments, and galaxies form in knots along the filaments.
16. Hidden Mass in Galaxies This X-ray image of an elliptical galaxy reveals hot, fast-moving gas even in the outer reaches of the galaxy. The visible mass of the galaxy is insufficient to hold onto it. (The dark circle shows the size of the galaxy when photographed in visible light. The X-ray image shows mass far outside the visible image.)
17.
18.
19.
20. Hidden Mass in Galaxies Rotation Curve - A Plot of Object Velocity vs. Distance Our Solar System
21. Activity #6a: Evidence for Hidden Mass There are ____ solar system planets presented on the graph. The planets, from the closest to the sun to the furthest, are ___________________________________ ______________________________. Using the graph, the velocities of the solar system planets, from the lowest value to the highest value, are _____________________ _________________________. Using the graph, the distances of the planets from the Sun are, from least to greatest, ____________________________________ ______________. In general, the further a planet is from the sun the ______ its velocity. The closer a planet is to the sun ______ its velocity. nine Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto approximately 48, 35, 30, 24, 13, 10, 7, 5, and 4 km/sec 0, 110, 150, 250, 800, 1500, 2800, 4500, and 6000 million km slower faster
22. Hidden Mass in Galaxies Rotation Curve - A Plot of Object Velocity vs. Distance Our Solar System
26. Hidden Mass in Galaxies What we expect for a galaxy if all the mass was concentrated in the central region. Compare expected velocities with actual velocities
32. The Hidden Lives of Galaxies Presentation available at http://imagine.gsfc.nasa.gov/docs/teachers/galaxies/galaxies.html
Editor's Notes
In this presentation, we’ll discuss the information about galaxies contained in “The Hidden Lives of Galaxies” poster and information booklet. We’ll also do a couple of classroom activities discussed in the booklet This version of the presentation includes information on galaxy formation, and has expanded approach for determining that galaxies have hidden mass [An image of the poster and text of the booklet are available on-line at http://imagine.gsfc.nasa.gov/docs/teachers/galaxies/galaxies.html] This version was uploaded to the Imagine site on 8/28/03 under the name Hidden_Lives_v2.ppt
To define what a galaxy is, we start with something close to home - our own solar system - and its place in our galaxy. The distance from the Earth to the Sun is 93 million miles (150 million km), or 8 light-minutes. That is, the time it takes light from the sun to reach Earth is 8 minutes. The entire solar system is 5.5 light-hours across. That is, light takes 5.5 hours to cross the solar system.
Neighboring stars can be grouped into stellar regions. The solar neighborhood is about 30 light-years across. A light year is the distance light travels in one year, and is about 6 trillion miles (9.5 trillion km) [Note that in some regions stars can be clustered quite closely together. Thus, some neighborhoods may be more crowded than others.]
A stellar region is just a small portion of a galaxy. A galaxy is a massive collection of stars, gas, and dust held together by its own gravity. Galaxies can range in size from 6,000 to 350,000 light-years across. Our own galaxy, the Milky Way, is about 105,000 light-years in diameter. The galaxy pictured here is the Andromeda Galaxy, which is the nearest large galaxy to our own. We think the Milky Way looks very much like Andromeda.
Galaxies are enormous in size. This slide shows the scale of our galaxy by analogy to the size of a cell in the human body. [A cell in the human body is about 50 microns (or 0.00005 meters) across.] Using this same analogy, the Andromeda Galaxy would be 22 miles away.
There are different types of galaxies, each with different characteristics. This slide presents the different galaxy types and their major features, one at time. The slide ends by showing a few additional examples of each type of galaxy. [This version works properly in Powerpoint for Mac OS X. The large image of the galaxy is now grouped with its descriptive text.]
At this point, participants can perform Activity #2 from “The Hidden Lives of Galaxies” booklet to test their knowledge of the types of galaxies. Use Transparencies #1 and #2 which accompany the booklet or which are available on the Imagine the Universe! website at http://imagine.gsfc.nasa.gov/docs/teachers/galaxies/transparencies/
This is according to http://zeus.ncsa.uiuc.edu:8080/Summers/galform.html Note that a bottom up theory still exits. Matter clumps on smaller scales and then becomes bound together into a galaxy.
Gas dissipates energy through collisions. Atoms in gas collide and heat up. The heat is dissipated in the infrared. The gas thus loses energy and collapses. If stars form quickly, then galaxy becomes elliptical. Angular momentum forms the gas into a disk. In ellipticals, gas hasn’t had time to collapse into a disk, and stars retain their initial orbits. If star formation proceeds more slowly, then the gas undergoes collisions and forms a disk under conservation of angular momentum. The stars don’t form until gas has collapsed into the disk. Globular clusters seem to form in the first epoch of star formation, just as the galaxies are forming. From http://zebu.uoregon.edu/~js/ast123/lectures/lec27.html
Mergers occur because the universe is actually pretty crowded ! From http://stardate.org/resources/galaxy/formation.html: “Mergers are common because the universe is crowded, at least on the galactic distance scale. The disk of the Milky Way, for example, spans about 100,000 light-years; the nearest major galaxy, the great spiral in Andromeda, lies about two million light-years away. That means the distance between these two galaxies is only about 20 times greater than the sizes of the galaxies themselves. That doesn't leave a lot of &quot;elbow room&quot; for galaxies.” See http://www.strw.leidenuniv.nl/~dokkum/mergers/info_eng.txt for nifty info about mergers. E.g it can take only a billion years for a merger to be complete.
From http://heritage.stsci.edu/1999/41/index.html Calculations indicate that IC 2163 is swinging past NGC 2207 in a counterclockwise direction, having made its closest approach 40 million years ago. However, IC 2163 does not have sufficient energy to escape from the gravitational pull of NGC 2207, and is destined to be pulled back and swing past the larger galaxy again in the future. They are destined to merge in the next few billion years. NGC 2207 has a diameter of 143,000 light years (44 kpc or 4'). IC 2163 has a diameter of 101,000 light years (31 kpc or 3'). They are 114 million light years (35 megaparsecs) away
The collision of these two galaxies sparks star formation (via collision of gas clouds) http://hubblesite.org/newscenter/archive/1997/34/ From the figure caption: The Hubble telescope has uncovered over 1,000 bright; young star clusters bursting to life in a brief, intense, brilliant &quot;fireworks show&quot; at the heart of a pair of colliding galaxies. The picture on the left provides a sweeping view of the two galaxies, called the Antennae. The green shape pinpoints Hubble's view. Hubble's close-up view [right] provides a detailed look at the &quot;fireworks&quot; at the center of this wreck. The respective cores of the twin galaxies are the orange blobs, left and right of center, crisscrossed by filaments of dark dust. A wide band of chaotic dust stretches between the cores of the two galaxies. The sweeping spiral-like patterns, traced by bright blue star clusters, are the result of a firestorm of star birth that was triggered by the collision.
Light is not only what we see with our eyes, but also comes in the form of radio waves, microwaves, infrared, ultraviolet, x-rays and gamma-rays. This figure shows common images representing the major portions of the spectrum. The gradations on the gray scale represent the changing wavelength of light as it goes from gamma-ray to radio. Astronomers use different regions of the e-m spectrum to determine different properties of objects. We often don’t get the whole picture until we look at an object in different wavelengths. Note that the X-ray image is not like the other images. The other images show the objects that emit that particular radiation. The medical x-ray show what is absorbed by the x-rays.
An X-ray picture of a galaxy looks very different from an optical picture. On the right is an optical picture of the Andromeda Galaxy. Note the familiar spiral structure, and the dark lanes of dust. On the left is an x-ray image of the Andromeda Galaxy taken by the ROSAT satellite. We no longer see the spiral structure, but instead individual objects. The inset shows a close-up of the central region of the Andromeda Galaxy taken by the Chandra X-ray Observatory. Again we see individual sources. But in both the Chandra and ROSAT images, we also see diffuse x-ray emission caused by hot gas.
These are some of the objects that emit x-rays in a galaxy: - Stars, like our Sun, emit X-rays from their hot coronas and active regions. - A Supernova Remnant is the remains of a massive star that has exploded. The explosion emits a shock wave that heats up surrounding gas. The gas becomes hot enough to glow in X-rays. - X-ray Binaries are star systems that consist of a normal star and a compact object such as a white dwarf, neutron star, or black hole. The compact object is what remains from a star after a supernova explosion. Material from the normal star flows toward the compact star, forming a disk of material around the compact star. As it nears the compact star, the gas in this disk becomes hot enough to emit x-rays. - Hot Gas permeates the galaxy and can surround a galaxy.
A number of elliptical galaxies are observed to have hot gas beyond the visible limits of the galaxy. The temperature of the gas is a measure of its velocity and energy. This gas is so hot (about 10 million degrees Kelvin, or 18 million degrees F), and consequently has such a high velocity, that it first appears to be escaping from the galaxy. Indeed, the amount of visible mass in the galaxy is insufficient to keep it from escaping. We know the gas is bound to the galaxy, because if it wasn’t it would have dissipated long ago. Hence, there must be some other matter that lies undetected in the galaxy. This additional matter gives the galaxy enough mass to hold onto the gas. This “hidden mass” is also known to astronomers as “dark matter”.
To further understand the evidence for hidden mass in galaxies, we go back to examining our own solar system. We first plot the velocity of the planets in their orbits around the sun (right hand vertical scale, in yellow) as a function of their distance from the sun (bottom scale, in yellow). This type of plot is known as a Rotation Curve. Ask audience members to describe how the velocity of the planets varies as the distance from the sun varies [as the distance increases, the velocity decreases]. You can use this slide with the following slide (on Activity 6a). May work best with this as a separate transparency on an overhead.
To better familiarize themselves with the rotation curve of the solar system, participants now perform the first part of Activity #6a in “The Hidden Lives of Galaxies Booklet.” Use Transparency #6 which accompanies the booklet or which is available on the Imagine the Universe! website at http://imagine.gsfc.nasa.gov/docs/teachers/galaxies/transparencies/ When participants are done, the presenter uses this slide to fill in the answers.
To further understand the evidence for hidden mass in galaxies, we go back to examining our own solar system. We first plot the velocity of the planets in their orbits around the sun (right hand vertical scale, in yellow) as a function of their distance from the sun (bottom scale, in yellow). This type of plot is known as a Rotation Curve. Ask audience members to describe how the velocity of the planets varies as the distance from the sun varies [as the distance increases, the velocity decreases]. The curve described is exactly that expected from Newton’s Law of Gravity.
We now compare the rotation curve for the solar system to that of a galaxy. Here we plot the velocities of stars going around the center of the galaxy (left hand vertical scale, in white) vs. their distance from the center of the galaxy (top scale, in white). “Kpc” stands for “kiloparsecs”, a distance used to measure large distances in galaxies (1 kpc = 3,260 light-years). We expect the rotation curve of a galaxy to be linear through the central bulge. This is because the central bulge rotates as a solid body. Outside the bulge, we expect the rotation curve to fall off with distance according to Newton’s Law of Gravity (similar to the solar system). Now show the actual rotation curve for a galaxy. Again, ask audience members to describe how the velocity varies as a function of distance [it rises steadily, and then at 10 kpc it becomes nearly constant]. We find that the velocities continue to rise outside the bulge, and eventually flatten out. The fact that velocities don’t follow Newton’s Gravity means that there is more mass in the galaxy than we can account for.
From observations of hot gas in galaxies and data from the Rotation Curves, we conclude that gas and stars in galaxies are moving faster than what we would expect from the visible mass of the galaxy. Note that by “visible”, we mean here mass detected at all wavelengths of the e-m spectrum, and not just optical. We find that only 10 % of the mass of the galaxy is detectable. WMAP results from Feb 2003 show that 4% of the universe is ordinary matter, 235 is cold dark matter, and 73% is dark energy.
Scientists have various candidates for what the hidden mass in galaxies could be. Hydrogen gas is abundant in galaxies, but there is still not enough of it. Massive Compact Halo Objects are objects such as black holes, neutron stars and brown dwarfs. Again, there just aren’t enough of them. The best candidate is Weakly Interacting Massive Particles. These are as yet undiscovered sub-atomic particles that interact weakly with normal matter but yet have mass. This is currently a very active field of particle physics and cosmology.
In this presentation, we’ll discuss the information about galaxies contained in “The Hidden Lives of Galaxies” poster and information booklet. We’ll also do a couple of classroom activities discussed in the booklet This version of the presentation includes information on galaxy formation, and has expanded approach for determining that galaxies have hidden mass [An image of the poster and text of the booklet are available on-line at http://imagine.gsfc.nasa.gov/docs/teachers/galaxies/galaxies.html]