introduction to galaxies in space.
chapter 9 earth and space class.
about the scientist edwin hubble.
and his theories. The study of asstronomy. space study of planets and galaxies.
It presents about normal galaxy and how it differs to other type of galaxy. The types of galaxies are also presented like spiral galaxies, barred spiral, ellipticals, lenticulars and irregular galaxies with examples and pictures for further explanation.
stars life .. how they are formed ... supernova , what is black hole, worm hole ..... very very interesting topic in very simple language and many images that make u understand easily
Types of galaxies
You can edit this powerpoint for your own presentation but don't re-upload.
I used hyperlink(especially on images) and alot of animation.
It presents about normal galaxy and how it differs to other type of galaxy. The types of galaxies are also presented like spiral galaxies, barred spiral, ellipticals, lenticulars and irregular galaxies with examples and pictures for further explanation.
stars life .. how they are formed ... supernova , what is black hole, worm hole ..... very very interesting topic in very simple language and many images that make u understand easily
Types of galaxies
You can edit this powerpoint for your own presentation but don't re-upload.
I used hyperlink(especially on images) and alot of animation.
1
KYA 306
Distance Scales
2
• Stellar, galactic, and extragalactic astrophysics, and cosmology all
require accurate distances.
• Search for standard candles (or in rare instances, standard
rulers). For the nearby Universe observed angular quantities scale
very simply to physical properties.
• The ideal standard candle would be something so close to the Sun
that it can be measured using trigonometric parallax, and bright
enough to be observed in the most distant known galaxies, with zero
intrinsic dispersion.
• Bootstrap approach, linking geometrically measured distances to
physical scaling relations that are more (or less) well understood
theoretically.
The Distance Ladder
€
3
Methods used at larger distances require calibration based on methods
used closer in. Red stars show the most widely used (and mostly, least
model-dependent) methods.
€
maser galaxies
4
The first reasonably
accurate
measurements of
distances to nearby
galaxies showed that
all but the closest are
receding away from
us at a rate that
increases linearly
with distance.
This observation is
the basis of modern
cosmology - defines
the expansion of the
universe.
The Hubble Constant
€
accurate distances and velocities allow the size and
age of the Universe to be measured, through the
value of the Hubble constant H0
5
1. Use a satellite (e.g., the ESA GAIA mission) to get the trigonometric
parallax of a large number of nearby Cepheid variable stars to
calibrate the zero point of the period-luminosity relation (Leavitt Law).
2. Use a space telescope to get Cepheid distances and tip of the red
giant branch distances to nearby galaxies (<25 Mpc), to calibrate
other methods based on the virial theorem and the dynamics of
individual galaxies (Tully-Fisher, Fundamental Plane).
3. Use TF, FP, and other methods to get distances beyond the point
where individual galaxy velocities contribute significantly to the
observed redshift.
4. Among the other: Type Ia supernovae, which are “standardisable
candles” (2011 Nobel Prize in physics for the acceleration of the
Universe).
Steps to the Hubble Constant
€
6
• Ground-based optical
parallaxes ~few milliarcseconds
➙ few 102 pc
• VLBI maser parallaxes ~10s of
microarcsec ➙ few 10s of kpc
• Satellite: Hipparcos
(1989-1993) ~ 1 mas for 105
stars (➙ ~1 kpc)
• Gaia (launched 2013, catalog
~2020) ~ 20 microarcsec for 108
stars ➙ 10% accuracy at
Galactic centre
Trigonometric Parallaxes
€
7
Intermediate mass stars,
evolved off the main
sequence to the helium-
burning stage, so they are
luminous.
Can be seen out to Virgo
cluster galaxies by the
Hubble Space Telescope.
Age few x108 yr, so only
observable in large numbers
in spiral galaxies, and the
larger irregular galaxies.
Cepheid Period-Luminosity
€
8
Radial pulsation in
supergiant stars
where the helium
ionisation zone is
at the proper depth
to excite global
oscillations.
Ce ...
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.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
2. What are Galaxies?
• Galaxy - a group of billions of stars and
their planets, gas, and dust that extends over
many thousands of light-years and forms a
unit within the universe.
Held together by gravitational forces, most of
the estimated 50 billion galaxies are shaped as
spirals and ellipses, with the remainder being
asymmetric.
3. The “Discovery” of Galaxies
At the beginning of
the 20th century, what
we now call spiral
galaxies were referred
to as “spiral nebulae”
and most astronomers
believed them to be
clouds of gas and
stars associated with
our own Milky Way.
Edwin P. Hubble (1889-1953)
(NOAO/AURA Photo)
4. The breakthrough came in
1924 when Edwin Hubble was
able to measure the distance
to the “Great Nebula in
Andromeda” (M 31, previous
slide) and found its distance to
be much larger than the
diameter of the Milky Way.
This meant that M 31, and by
extension other spiral nebulae,
were galaxies in their own
right, comparable to or even
larger than the Milky Way.
5. Galaxy Classification
In 1924, Edwin Hubble
divided galaxies into
different “classes”
based on their
appearance.
Why begin here?
•Hubble classification serves as the
basic language of the field.
•The morphological sequence reflects
a fundamental physical and, in some
ways, evolutionary sequence, which
offers important clues to galactic
structure, formation and evolution.
6. GALAXIES, GALAXIES, GALAXIES!
A dime a dozen… just one of a 100,000,000,000!
1. Galaxy Classification
Ellipticals
Dwarf Ellipticals
Spirals
Barred Spirals
Irregulars
2. Measuring Properties
of Galaxies
Distances
Sizes
Luminosities
Masses
Dark Matter?
8. Spiral Galaxies
•Disk + spiral arms + bulge (usually)
•Subtype a b c defined by 3 criteria:
•Bulge/disk luminosity ratio
•Sa: B/D>1 Sc: B/D<0.2
•Spiral pitch angle
•Sa: tightly wound arms Sc: loosely wound arms
•Degree of resolution into knots, HII regions, etc.
9. Spiral Galaxies
Comprise about 2/3rds of bright galaxies
Grand Design Spiral - well defined spiral structure
Flocculent - less organized spiral design
Spirals clearly contain much gas and dust
Most starlight is from young, blue stars - ongoing star
formation
Sizes - radius = 10 to 30 kpc
Masses - M = 107 to 1011 Msun
Milky Way and Andromeda are both
bright, spirals
MV ~ -21 or LV ~ 2 x 1010 LV,sun
10. Spiral Galaxies
Spirals are classified by their relative amount of
disk and bulge components.
We designate these Sa, Sb, Sc, in order of
decreasing bulge to disk ratio.
More bulge
More disk
Barred spirals are
called SBa, SBb, SBc
More disk means
more star formation!
11. Elliptical Galaxies
•Smooth structure and symmetric, elliptical contours
•Subtype E0 - E7 defined by flattening
•En where n = 10(a-b)/a
a and b are the projected major and minor axes
(not necessarily a good indicator of the true 3-D shape)
12. S0 Galaxies (Lenticulars)
•Smooth, central brightness concentration (bulge similar to E) surrounded by
a large region of less steeply declining brightness (similar to a disk)
•No spiral arm structure but some contain dust and gas
•Originally thought to be transition objects between Sa and E but typical S0 is
1-2 mags fainter than typical Sa, E (van den Bergh 1998)
13. Irregular Galaxies
•No morphological symmetry
•Lots of young, blue stars and interstellar material
•Smaller than most spirals and elliptical galaxies
•Two major subtypes:
•Irr I: spiral-like but without defined arms, show bright knots with O,B stars
•Irr II: contain many dust lanes and gas filaments (e.g. M82) - explosive
M82-Irr II
NGC 4485-Irr II LMC - Irr I
14. Limitations of the (original) Hubble Classification Scheme
1. Only includes massive galaxies (doesn’t include dwarf spheroidals,
dwarf irregulars, blue compact dwarfs)
2. Three different parameters for classifying spirals is unsatisfactory
because the parameters are not perfectly correlated.
3. Bars are not all-or-nothing. There is a continuum of bar strengths.
General trends within Hubble
sequence E Sc:
•Decreasing Bulge/Disk
•Decreasing stellar age
•Increasing fractional gas
content
•Increasing ongoing star
formation
15. de Vaucouleurs’ Revised Hubble Classification System
(de Vaucouleurs 1958, Handbuch der Phys. 53, 275)
(de Vaucouleurs2 1964, Reference Catalog of Bright Galaxies)
Basic idea: retain Hubble system, but add lots of additional options:
Rings (inner and outer), range of bar-like structures….
No Bar
Bar
Spiral
shaped
Ring
shaped
Cross section of diagram
E E+ S0- S0 S0+
Sa Sb Sc Sd Sm Im
Limitations:
Rings and bars are not independent
Does not take into consideration mass or other important
parameters.
16. Barred Spiral Galaxies
•Contain a linear feature of nearly uniform
brightness centered on nucleus
•Subclasses follow those of spirals with
subtypes a b and c
MW may be SBb,
depending on
prominence of
the bar.
17. The Hubble Deep Field
The longest, deepest exposure ever taken. Was an empty piece of sky!
From this image, we can estimate
the number of galaxies in the
universe!
1. Count the number of
galaxies in this image
2. Measure angular area on
the sky of this image
3. Figure out how many
images of this size needed
to cover entire sky
4. Multiply that number
(from 3.) by the number
of galaxies in this image
(from 1.)
18. Galaxies are the Fundamental “Ecosystems” of the Universe
• are cosmic engines that turn gas into stars and stars into gas
• between them no star formation occurs; “nothing happens” in intergalactic space
• are recent discovery (by Edwin Hubble in late 1920’s)
• can be classified my morphology (shapes and sizes)
Three Main Types of Galaxies:
• Ellipticals - galaxies are pure bulge, no disk component
• Spirals - galaxies contain varying amounts of disk component
from mostly bulge with barely detectable disks to
those totally dominated by their disks
• Irregulars - galaxies are… well. Odd.
19. Elliptical Galaxies
Names of E galaxies give their shape.
E0 is round. E6 is elongated.
The way you name an E galaxy is to
measure its “major” and “minor” axis
and plug it into the formula above.
An Example of an E0 galaxy. The
bright objects surrounding it are its
own globular clusters.
Elliptical galaxies are affectionately called “E” galaxies. They can be extremely
large and massive. This galaxy is 2 million light years across.
The size of the Milky Way in comparison!
20. More E Galaxies
Here is an example of an E6 galaxy. Note
how well it fits the definition of an E6.
Note that it has smooth brightness profile,
that there are no features due to dust and
gas.
Note how this little formula is
used simply by looking at the
photograph. We use computers
to make these measurements.
Many E galaxies reside in center of groups
or clusters of galaxies.
Note the E0 (to the right) and the E3 near
the center of the cluster.
21. Disks vs. Bulges
Disks:
• flattened systems that rotate
• orbits of stars and gas are “circular”, rotating about disk axis
• star formation is on-going; it is can be fairly constant over the age of the galaxy
• gas and dust mass fraction is roughly 10-50% of full disk
• due on-going star formation, ages of stars widely range from age of galaxy to new
• spiral arms form as sustained density waves; where majority of star formation occurs
Bulges:
• spheriodal systems with little or no rotation
• orbits of stars are randomly oriented and highly eccentric (some are radial)
• star formation complete long ago; gas consumed efficiently long ago
• ages of stars are mainly old; most as old as the galaxy
• very little to know gas; it has been converted to stars already
• overall structure is smooth- no clumpy areas like analogous to spiral arms in disks
22. The Large and Small Magellanic “Clouds”
The SMC and LMC are small Irregular
galaxies that are satellites of the Milky
Way Galaxy.
The LMC is still
forming stars.
The SMC is not
forming new stars.
23. Dwarf Elliptical Dwarf Irregular
The Garbage Can of Galaxy Classification
… and there are more of these types of galaxies than any other type!
There may be lots of them, but they are not very luminous or very
massive, so they do not contribute to the total integrated galaxy
luminosity or mass in the universe.
25. Clusters of Galaxies
Rather than occurring
individually in space,
galaxies are grouped in
clusters ranging in size
from a few dozens to
thousands of galaxies. The
Coma Cluster, shown at
right, is 300 million light
years from the Milky Way
and contains more than
1,000 (and possibly as
many as 10,000) galaxies.
The Milky Way is a
member of a small cluster
called the Local Group
which contains about 40
galaxies. The largest
member of the Local
Group is M 31, with the
Milky Way coming in
second in size.
(NOAO/AURA Photo)
26. Getting the Distances to Galaxies is a “Big Industry”
solar system 10 A.U. radar ranging
Local Galaxy 100 pc stellar parallax
Across Galaxy 10,000 pc spectroscopic
“parallax”
Nearby galaxies 15 Mpc Variable stars
Distant galaxies 200 Mpc Standard candle
and “Tully-Fisher”
Location Distance Method
1 Mpc = 1 million parsecs
We have studied stellar parallax, and variable stars.
Spectroscopic parallax is simply comparison of brightness of identical stars.
Standard candle is comparison of brightness of identical supernovae explosions.
Tully-Fisher is a way to measure galaxy luminosity from its rotations speed. More …
The Distance Ladder
d = constant x (L/B)1/2
27. L = constant x (velocity)4
d = constant x (L/B)1/2
Tully-Fisher Distance Indicator
Recall, luminosity of stars scales with mass of stars… therefore, luminosity of galaxy
scales with number of stars (and thus, mass of stars). Thus, luminosity of galaxy gives
mass of galaxy.
Going backwards… measure the velocity to “weigh” the galaxy to obtain luminosity.
velocity
Doppler velocity map of galaxy.
28. The Hubble Law
The problem is that 200 Mpc is nothing!
Well, it turns out that there is another
indicator for extreme distances.
The Hubble Law
The further away a galaxy is, the
greater is its redshift.
Red Blue
(As you can see, it is not perfect.)
29. Hubble Law Takes us All the Way Out
Implies that Galaxies are “flying away” and
that the speed with which they are moving
away is proportional to there distance away.
The further away the galaxy, the faster it is
receding from us. (more on this later…)
The distance scale revisited.
velocity = constant x distance
The constant is called Hubble’s constant.
It is designated as H0. Pronounced “H not”.
velocity = H0 x distance
31. M31 - The
Great
Spiral
Galaxy in
Andromeda
This nearby galaxy in
the Local Group of
galaxies, of which the
Milky Way is a
member, is 2.5 million
light years away.
(NOAO/AURA Photos)
32. The
Nuclear
Bulge of
M31
(NOAO/AURA Photos)
Young stars have
formed along the
foreground spiral arm.
M31’s two satellite
galaxies M32 and NGC
205, both dwarf
elliptical galaxies, are
in the bottom center
and upper right.
35. Barred Spiral Galaxies
The spiral galaxies M 91 (left) and M 109 (right) have bars across their nuclei from which spiral arms
unwind. In virtually all spirals (barred or not) the galaxies rotate such that the spiral arms trail behind in
the rotation. The Milky Way is thought to be a barred spiral galaxy. (NOAO/AURA Photos)
36. Types of Galaxies II. Ellipticals
Elliptical galaxies lack spiral arms and dust
and contain stars that are generally
identified as being old. The elliptical galaxies
M 32 (below) and M 110 (right) show
varying degrees of ellipticity.
(NOAO/AURA Photos)
37. Types of Galaxies III. Irregulars
Irregular galaxies lack any specific
form and contain stars, gas and dust
generally associated with a youth.
The irregular galaxy at right is the
Large Magellanic Cloud, a satellite
of the Milky Way located about
180,000 light years from the sun.
The LMC is about 60,000 light years
across. The bright reddish feature in
the upper right is the “Tarantula
Nebula” a region of star formation
in the LMC. (NOAO/AURA Photo)
39. Gravitational Lensing in Abell 2218 Cluster
Hubble Space Telescope Image
As predicted by Einstein’s General Theory of Relativity, a compact intervening object is bending and
distorting light from individual members of this cluster so that we see a halo effect.
40. Galaxies in Collision
In this close encounter between two spiral galaxies, their arms are dramatically warped and
massive star formation is triggered when the hydrogen gas clouds in the two collide. It is believed
the Milky Way may have “cannibalized” small galaxies in the past through collision.
Hubble Space Telescope Image
42. Hubble Space Telescope Image
Active Galaxies I.
The galaxy NGC 7742 is an otherwise normal
spiral galaxy except for its extraordinarily
bright nucleus that outshines the rest of the
galaxy. Such galaxies, i.e. spirals with
extremely bright nuclei, form a class of active
galaxies known as Seyfert galaxies.
43. Active Galaxies II.
The elliptical galaxy M87, shown below in a
wide-field ground-based image, has a very
bright, point-like nucleus from which a jet of
material emanates. The jet is seen in great
detail from an HST image at right.
Hubble Space Telescope Image
44. Active Galaxies III.
This image shows the spiral
galaxy NGC 4319 and the quasar
Markarian 205. The distance to
NGC is 80 million light years,
which Mkn 205 is 14 times
farther away at a distance of 1
billion light year.
The very distant quasar is nearly
as bright as the much closer
galaxy. The extraordinary
brightness of quasars, which is a
blending of the term quasi-stellar
radio source, indicates that some
incredibly powerful mechanism
must be producing enormous
amounts of energy from a small
volume of space.
Hubble Space Telescope Image
Mkn 205
NGC 4139
45. A Lensed Quasar
National Optical Astronomy Observatories Image
An intervening galaxy between us
and this distant quasar is causing
light from the quasar to be bent
along curved paths that give rise
to an Einstein cross, a
phenomenon predicted by
Einstein’s General Theory of
Relativity.