NRT polarimetry and neutron star mergers - Nam 2019Joseph Fernandez
Talk given in the National Astronomy Meeting 2019, Lancaster, UK.
A large number of neutron star mergers will be detected by LIGO/Virgo in the coming years. GW170817 confirmed that neutron star mergers would actually produce relativistic outflows (e.g. relativistic jets and cocoon). The polarimetry by LT and NRT would enable us to study the properties of the outflow in details (i.e. magnetic field structure/strength, and its angular dependence). We discuss polarization signals in the outflow emission, and we show the expected signal distributions for an upcoming neutron star merger sample.
NRT polarimetry and neutron star mergers - Nam 2019Joseph Fernandez
Talk given in the National Astronomy Meeting 2019, Lancaster, UK.
A large number of neutron star mergers will be detected by LIGO/Virgo in the coming years. GW170817 confirmed that neutron star mergers would actually produce relativistic outflows (e.g. relativistic jets and cocoon). The polarimetry by LT and NRT would enable us to study the properties of the outflow in details (i.e. magnetic field structure/strength, and its angular dependence). We discuss polarization signals in the outflow emission, and we show the expected signal distributions for an upcoming neutron star merger sample.
Almost forty years ago the Voyager 1
spacecraft performed its first
flyby of Jupiter, and detected very
low frequency radio emissions called
whistlers that were attributed to lightning
on the gas giant1. Combined with optical
images from the dark side of the planet2
these observations directly confirmed
the existence of lightning in the Jovian
atmosphere, which had been hypothesized
a few years earlier in order to explain the
observed abundance of acetylene3. Now,
the Juno spacecraft is visiting the giant
planet and revealing new, and sometimes
surprising features of Jovian lightning.
Writing in Nature, Shannon Brown et al.4
have measured the high-frequency
components of the lightning emissions for
the first time, placing new constraints on the
speed and nature of the lightning process.
In complementary observations reported in
Nature Astronomy, Ivana Kolmašová et al.5
Discovery of rapid whistlers close to Jupiter implying lightning rates simila...Sérgio Sacani
Electrical currents in atmospheric lightning strokes generate
impulsive radio waves in a broad range of frequencies, called
atmospherics. These waves can be modified by their passage
through the plasma environment of a planet into the form of
dispersed whistlers1. In the Io plasma torus around Jupiter,
Voyager 1 detected whistlers as several-seconds-long slowly
falling tones at audible frequencies2. These measurements
were the first evidence of lightning at Jupiter. Subsequently,
Jovian lightning was observed by optical cameras on board
several spacecraft in the form of localized flashes of light3–7.
Here, we show measurements by the Waves instrument8
on board the Juno spacecraft9–11 that indicate observations
of Jovian rapid whistlers: a form of dispersed atmospherics
at extremely short timescales of several milliseconds to
several tens of milliseconds. On the basis of these measurements,
we report over 1,600 lightning detections, the largest
set obtained to date. The data were acquired during close
approaches to Jupiter between August 2016 and September
2017, at radial distances below 5 Jovian radii. We detected up
to four lightning strokes per second, similar to rates in thunderstorms
on Earth12 and six times the peak rates from the
Voyager 1 observations13.
Spectral signatures are the specific combination of emitted, reflected or absorbed electromagnetic radiation (EM) at varying wavelengths which can uniquely identify an object. Here, i have focused on the spectral signature of water and the various micro-process that are responsible for it.
Speaker: Michael Hippke
Affiliation: Sonneberg Observatory
Title: ''Interstellar communication: What works (not so) well and why? "
Abstract: Our nearest neighbor star, Alpha Centauri C, has a planet in the habitable zone. The Russian billionaire Yuri Milnor funds research to send an exploration probe there. Obtaining remote observational data from such a probe is not trivial because of minimal instrumentation (gram scale) and large distances (pc). Together, we follow the long journey of a photon from the transmitter beam through the interstellar dust and gas, atmospheric turbulence, and other obstacles, before finally arriving in the receiver on Earth. We discuss wavelength/frequency choices, gravitational lensing, and particles other than photons, such as Neutrinos. We conclude by asking the "big picture" question: Only when we understand how to communicate efficiently over interstellar communications, we can hope to learn how to receive such communications from other civilizations, if they exist. Are radio waves the best choice?
Multimessenger observations of a flaring blazar coincident with high-energy n...Sérgio Sacani
Neutrinos are tracers of
cosmic-ray acceleration: electrically neutral
and traveling at nearly the speed of light, they
can escape the densest environments and may
be traced back to their source of origin. Highenergy
neutrinos are expected to be produced
in blazars: intense extragalactic radio, optical,
x-ray, and,in some cases, g-ray sources
characterized by relativistic jets of
plasma pointing close to our line of
sight. Blazars are among the most
powerful objects in the Universe and
are widely speculated to be sources
of high-energy cosmic rays. These cosmic
rays generate high-energy neutrinos
and g-rays, which are produced
when the cosmic rays accelerated in
the jet interact with nearby gas or
photons. On 22 September 2017, the
cubic-kilometer IceCube Neutrino
Observatory detected a ~290-TeV
neutrino from a direction consistent
with the flaring g-ray blazar TXS
0506+056. We report the details of
this observation and the results of a
multiwavelength follow-up campaign
Almost forty years ago the Voyager 1
spacecraft performed its first
flyby of Jupiter, and detected very
low frequency radio emissions called
whistlers that were attributed to lightning
on the gas giant1. Combined with optical
images from the dark side of the planet2
these observations directly confirmed
the existence of lightning in the Jovian
atmosphere, which had been hypothesized
a few years earlier in order to explain the
observed abundance of acetylene3. Now,
the Juno spacecraft is visiting the giant
planet and revealing new, and sometimes
surprising features of Jovian lightning.
Writing in Nature, Shannon Brown et al.4
have measured the high-frequency
components of the lightning emissions for
the first time, placing new constraints on the
speed and nature of the lightning process.
In complementary observations reported in
Nature Astronomy, Ivana Kolmašová et al.5
Discovery of rapid whistlers close to Jupiter implying lightning rates simila...Sérgio Sacani
Electrical currents in atmospheric lightning strokes generate
impulsive radio waves in a broad range of frequencies, called
atmospherics. These waves can be modified by their passage
through the plasma environment of a planet into the form of
dispersed whistlers1. In the Io plasma torus around Jupiter,
Voyager 1 detected whistlers as several-seconds-long slowly
falling tones at audible frequencies2. These measurements
were the first evidence of lightning at Jupiter. Subsequently,
Jovian lightning was observed by optical cameras on board
several spacecraft in the form of localized flashes of light3–7.
Here, we show measurements by the Waves instrument8
on board the Juno spacecraft9–11 that indicate observations
of Jovian rapid whistlers: a form of dispersed atmospherics
at extremely short timescales of several milliseconds to
several tens of milliseconds. On the basis of these measurements,
we report over 1,600 lightning detections, the largest
set obtained to date. The data were acquired during close
approaches to Jupiter between August 2016 and September
2017, at radial distances below 5 Jovian radii. We detected up
to four lightning strokes per second, similar to rates in thunderstorms
on Earth12 and six times the peak rates from the
Voyager 1 observations13.
Spectral signatures are the specific combination of emitted, reflected or absorbed electromagnetic radiation (EM) at varying wavelengths which can uniquely identify an object. Here, i have focused on the spectral signature of water and the various micro-process that are responsible for it.
Speaker: Michael Hippke
Affiliation: Sonneberg Observatory
Title: ''Interstellar communication: What works (not so) well and why? "
Abstract: Our nearest neighbor star, Alpha Centauri C, has a planet in the habitable zone. The Russian billionaire Yuri Milnor funds research to send an exploration probe there. Obtaining remote observational data from such a probe is not trivial because of minimal instrumentation (gram scale) and large distances (pc). Together, we follow the long journey of a photon from the transmitter beam through the interstellar dust and gas, atmospheric turbulence, and other obstacles, before finally arriving in the receiver on Earth. We discuss wavelength/frequency choices, gravitational lensing, and particles other than photons, such as Neutrinos. We conclude by asking the "big picture" question: Only when we understand how to communicate efficiently over interstellar communications, we can hope to learn how to receive such communications from other civilizations, if they exist. Are radio waves the best choice?
Multimessenger observations of a flaring blazar coincident with high-energy n...Sérgio Sacani
Neutrinos are tracers of
cosmic-ray acceleration: electrically neutral
and traveling at nearly the speed of light, they
can escape the densest environments and may
be traced back to their source of origin. Highenergy
neutrinos are expected to be produced
in blazars: intense extragalactic radio, optical,
x-ray, and,in some cases, g-ray sources
characterized by relativistic jets of
plasma pointing close to our line of
sight. Blazars are among the most
powerful objects in the Universe and
are widely speculated to be sources
of high-energy cosmic rays. These cosmic
rays generate high-energy neutrinos
and g-rays, which are produced
when the cosmic rays accelerated in
the jet interact with nearby gas or
photons. On 22 September 2017, the
cubic-kilometer IceCube Neutrino
Observatory detected a ~290-TeV
neutrino from a direction consistent
with the flaring g-ray blazar TXS
0506+056. We report the details of
this observation and the results of a
multiwavelength follow-up campaign
GEORG Geothermal Workshop 2016
Presentation Title: Volcano-tectonostratigraphic characteristics of the Jan Mayen microcontinent and Iceland shelf area, lessons learned for geothermal exploration
GEORG Geothermal Workshop 2016
Presentation Title: Hydrogen Sulfide concentration in the vicinity of the Reykjavik Capital area due to two Geothermal Power Plants
GEORG Geothermal Workshop 2016
Presentation Title: Willingness to pay for the preservation of geothermal areas in Iceland – the contingent valuation studies of Eldvörp and Hverahl
GEORG Geothermal Workshop 2016 SESSION B2, Midstream. Presentation title: Feasibility study for utilizing an ORC cycle to cool medium temperature geothermal fluid to appropriate temperature for use at Seltjarnarnes district heating
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
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Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
1. Magma reflection imaging in Krafla, Iceland
using microearthquake sources
Doyeon Kim1, Larry D. Brown1, Knútur Árnason2, Kristján
Águstsson2, and Hanna Blanck2
1Earth and Atmospheric Sciences, Cornell University, Ithaca,
New York, USA
2Iceland Geosurvey (ISOR), Reykjavik, Iceland
2. Introduction
• Distribution and movement of magma in the
earth has been a critical concern
• Magma chambers vs sill or dyke complexes
• Role of viscosity & density in the magma transportation
• Relative mixing of original magma with host rocks
during ascent
• Recognition of precursors to major eruptive events
• Energy source for geothermal system
• Societal concerns
3. Imaging magma
Wei et al., 2001
Huang et al., 2015
Chmielowski et al., 1999
Seismic tomography in Yellowstone Receiver functions in Altiplano-Puna magma body
Magnetotelluric in Tibetan plateau
4. Seismic Reflection Imaging magma
Brown et al., 1996Bright spots beneath the Tibetan Plateau
deVoogd et al., 1986
Bright spots in death valley
5. Seismic Reflection Imaging magma
Matsumoto et al., 1996
Bright spots beneath Northeastern Japan arc
Sanford et al., 1977
Bright spots beneath Rio Grande Rift
6. Case real world:
- NOT random nor sufficient sources
Developing the idea further by
using more stations with near
offset for stacking:
Virtual reflection
Can become an artifact
Imaging microearthquake with
seismic interferometry
7. Imaging microearthquake with
seismic interferometry
In nature, earthquakes are not random
Extracting body waves with SI has been spotty at
best
Our focus is based on redatuming of selected
sources
Virtual Reflection Seismic Profiling (VRSP)
8. Drilled into the magma
Geological model of Krafla modified from
Ármannsson et al. [2014].
9. DRG network, Krafla
Deep Roots of Geothermal systems (DRG) project, supported by ISOR, the GEOthermal
Research Group (GEORG) and Icelandic power companies, 20 seismic stations were
deployed at 200m spacing
11. Selected sources
Real sources close to the virtual
source
close to the line we are imaging
the same subsurface
145 and 137
microearthquakes were
extracted for imaging
beneath array 1 and 2
respectively.
Array 2Array 1
12. Example of virtual shot gather from
selected sources
-virtual direct wave with apparent velocities
that are consistent with those measured by
locally (IMAGE-VSP survey)
-more traces which contains reproducible
virtual reflections by crosscorrelation.
13. VSRP section
a) errors in the event locations
b) S wave contributions to the cross-correlation functions,
c) variations in microearthquake focal which could result in polarity changes that degrade the stack
d) contributions from converted phases (e.g. S to P).
14. 3D VRSP in Krafla
R1: corresponds to a depth about 2.75km, comparable to the body intersected by IDDP-1
R2: potential reflection from its base if it were 500 m thick.
R3: represent energy arriving from out of the plain of the section (e.g. sideswipe)
R4: could mark the top of the postulated deeper chamber/ another intrusion/brine or steam??
17. Conclusion
• Microearthquakes are valuable untapped source for high
resolution reflection imaging
• Virtual reflection at Krafla observed at depth which
corresponds to the drilled magma
• Really need dense 2D surface recording array
• New seismic technology facilitates relatively low cost
3D/4D reflection imaging with microearthquakes
• Potential applications
– Geothermal systems
– Active volcanoes
– Aftershock sequences
– Active faults (ongoing seismicity)
– Hydraulic fracturing
18. We thank ISOR, GEORG, and the National Power Company,
Iceland for providing the data
Acknowledgments
ISOR thanks Karin Berglund at Uppsala University and
Pálmar Sigurðsson at ISOR for their dedication to the
fieldwork in Krafla.
Special thanks to Gylfi Hersir for continuous support
20. Virtual Reflection Profiling (VRP)
If a subsurface source is located directly below a receiver,
1. autocorreation of the transmission response ≈ reflection response from an
zero offset surface source
2. a number of randomly distributed sources in depth will cancel out the
“artifact”
21. Virtual Seismic Reflection Profiling
• Highest resolution: reflection seismology
• Expensive for active sources
• Effective bandwidth is limited for current passive techniques –
relatively low resolution image
Use reflections from local earthquakes with recent advance in seismic
instrumentation (dense array) – Virtual Seismic Reflection Profiling (VSPR)
22. Imaging microearthquake with
seismic interferometry
Treatment of ambient noise
P coda wave interferometry
Multidimensional deconvolution
Extracting body wave with SI has been challenging
Nishitsuji et al., 2016Ito et al., 2012
23. Step3.
coherent energy bands increases as the number of events used in the stack increases
we found relatively little improvement in the signal-to-noise as the number of events increase
beyond 40
24. Results: VSRP
lateral coherent energy is more evident along Array 1 than Array 2 (Figure 11).
We attribute this to the much smaller number of suitably located earthquakes
available to produce Array 1 compared to Array 2.
25. Autocorrelations
Autocorrelating works the best if sources are
located directly beneath every station
The effective spatial sampling is irregular, and
there is little basis for discriminating
reflections from virtual sources at the surface
from coherent artifacts
26. Treat as ambient “noise”
(a) Entire earthquakes recorded
(b) Regional earthquakes with coda wave interferometry with multidimensional deconvolution
(c) Local earthquakes with coda wave interferometry with multidimensional deconvolution
Editor's Notes
This work involves myself, Larry brown who is my advisor in Cornell, and our fellow collaborators in ISOR Knutur, Krishan, and Hanna.
We’d like to present Magma reflection imaging in Krafla, using microeathquakes sources
To begin with, distribution and movement of magma in the earth has been a critical interest for decades and this includes
the most fundamental question about the structure of magma chamber whether it is a sill or dyke complexes, magma transportation, mixing with host rocks during ascent,
and recognition of precursors to major eruptive events.
Besides geological perspective, we are also interested in energy production for geothermal system (that’s why we are gathered up around here) and last but not least
Sociietal concern highly associated with magma eruption itself.
For seismologist like myself, I am most interested in whether we can image/or detect this marvelous structure in subsurface.
Perhaps the answer to this would be yes we can detect them and here are some well-known examples.
On the left hand side, seismic tomography reveals low velocity anomaly in subsurface and this particular example shows the magma related structures in Yellowstone.
Another technique which people often use when trying to imaging the discontinuity of the earth, they use receiver function with teleseismic earthquakes.
Also there is Magnetotelluirc method which is one of powerful measurement that can detect liquid body in subsurface.
However, these examples that I show here rather gives you a low resolution picture of subsurface. Can we do better than this?
Yes we can by using seismic reflection techniques with active sources on the surface.
Here is a great example of imaging the magma in high resolution and the top figure shows bright spots beneath the Tibetan plateau.
You can even point out where exactly is indicated as YDR…
Figure at the bottom also shows another example using vibroseis truck at the surface and you can see a clear bright spot in death valley.
There is also another however here again and its mainly because of the cost of using active sources itself not to mention other logistical obstacles of using them.
The other end of the spectrum, people have been using natural sources.
On the left, you can see the result from the classic paper by Sandford et al., 1977 and they used the direct measurement of the reflection phase from
Microearhquakes. These reflections are from magma beneath Rio Grand Rfit.
On the right hand side, a similar approach was applied by Japanese crews and they attempt to image bright spots benearth Northeastern Japan arc system.
One of the popular technique that can be used with seismic reflection imaging nowadays is seismic interferometry.
The idea is that if you have a source in subsurface and you have signals collected by the source…
Xcorr direct wave with ghost reflection you get a virtual reflection and this process kinematically redatum the source to the surface.
This type of imaging also involves an artifact which is a product of a direct wave and a downgoing wave (primary reflection from an interface) and it rises
a nonphysical arrivals. However in theory if you have sources that are randomly distributed in space and you have a lot of them you can cancel out this artifact while enhancing
the virtual reflection.
The problem here is that the eathquakes does not happen random in space.
And since the earthquakes are not random in real case, extracting body waves using SI has been spotty at best.
So our approach is based on using SI to redatum the deep sources to the surface however we apply it to the selected sources in subsurface and
we named this as virtual reflection seismic profiling in short VRSP
To test this idea, Krafla is a unique and a obvious to place to do so since we have an experience of drilling into the magma.
In other words, we know the known target at depth.
The data we used is from DRG network in Krafla. Since Knutur gave us a great talk yesterday about this network I am not going to spend too much time on it.
I used two arrays, array 1 and array2 in the figure and you can also see the microearthquakes that are recorded by this network in green circles.
Here are some example of earthquake we collected.
On the left you see a microearthquake its magnitude of 1. P and S waves are clear so as the reflection from 2km depth in between.
On the right you see a regional eq .. You can also..
As I mentioned, we selected these eqs before redatuming them to the surface and the criteria is as follows.
Suppose you have an array of receivers in red with a source that has an offset to the side in green. If this source was an active source on the surface,
the reflection point will be sampling the midpoint between the two as shown in gray dots.
Now if this source is an earthquake you can see the reflection point from the ghost reflection approach slighted closer to the array based on Snell’s law.
So our goal here is to select earthquakes that are close enough to the array so that we can place these blue dots into the CMP bins that are conventionally used in
Reflection imaging technique. And the CMP bins for our data is on the righthand sided.
Fix the figure
Real value here is
Always potential of doing time lapse 4D
Slide
Real value here is
Always potential of doing time lapse 4D
Slide
Can use modeling result…
micro
Real value here is
Always potential of doing time lapse 4D
Slide
optional
optional
Often used.. All of the result shown in Figure 8 provides little indication of the coherent energy in contrast to what we consistently observed from VRSP for the selected microearthquakes.
optional