A&C Reference Library - Astronomy & Cosmology Resources

[marcus]

Titan data

Here is a link with some physical data about Titan
http://library.thinkquest.org/18188/english/planets/saturn/moons/titan.htm
I will try to get some other links, just to confirm the numbers.
they say

mass 1.35E23 kilogram (2.259 percent of earth)
radius 2575 km
density 1.88
distance from Saturn 1,221,850 km
orbital period 15.945 days
surface temperature -178 celsius
surface pressure 1.6 bar (60 percent more pressure than earth)
escape velocity 2.65 km/second

this data is before Huygens and some of it might have already been improved on.
If anybody knows some better please post it. TIA.

Possibly the most reliable source is a JPL site I just found:
http://ssd.jpl.nasa.gov/sat_props.html
http://ssd.jpl.nasa.gov/sat_elem.html

Here is a sample---BTW they don't show mass in kilograms, they show GM (which is what astronomers measure, and then infer mass from it)

Titan
GM (km3/sec2) 8978.0 ± 0.8
Radius (km) 2575.5 ± 2.
Density (g/cm3) 1.880 ± 0.004

this site was updated as recently as November 2004
just for comparison here's what JPL NASA has for 4 jovians

Io
5959.916 ± 0.012
1821.6 ± 0.5
3.528 ± 0.006


Europa
3202.739 ± 0.009
1560.8 ± 0.5
3.013 ± 0.005


Ganymede
9887.834 ± 0.017
2631.2 ± 1.7
1.942 ± 0.005


Callisto
7179.289 ± 0.013
2410.3 ± 1.5
1.834 ± 0.004

Here's the main address
http://ssd.jpl.nasa.gov/

 

[marcus]

intriguing new technique for measuring the mass of a star
http://arxiv.org/abs/astro-ph/0501548

European Space Agency page of facts about Titan
http://www.esa.int/SPECIALS/Cassini-Huygens/SEMMF2HHZTD_0.html

 

[wolram]

http://xyz.lanl.gov/pdf/gr-qc/0501041
The basics of gravitational wave theory
47 pages jan 2005
Please discard this if it is of no use.

 

[Physik]

Orbital Mechanics Basics

This is a very cool site that explains Orbital Mechanics from the beginning, and explains all the math steps of the equations. (Unlike some other sites I've been to.)

http://www.braeunig.us/space/orbmech.htm

 

[turbo]

On-demand streaming video lectures...

I have been plowing through the Vega lectures (including the wonderful Feynman series) and linked resources, and found that this man has linked streaming videos from academic programs all over the world. If you enjoy science, I know what you'll be doing for the next few months.

http://web.mit.edu/people/cabi/Links/physics_seminar_videos.htm

 

[marcus]

Lineweaver and Davis in March SciAm

http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147

Popular written feature article "Misconceptions about BigBang"
Here are some sample "sidebars" of the article. Each has one or more visual diagrams with a wrong answer discussed and a right answer explained.


http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p39.gif
What kind of explosion was the big bang?

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p40.gif
Can galaxies recede faster than light?

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p42.gif
Can we see galaxies receding faster than light?

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p43.gif
Why is there a cosmic redshift?

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p44.gif
How large is the observable universe?

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p45.gif
Do objects inside the universe expand, too?

 

[marcus]

a NASA resource for teachers called "ask a high energy astronomer"
http://imagine.gsfc.nasa.gov/docs/ask_astro/ask_an_astronomer.html

when I sampled it I found a lot dated in the late 1990s, which can be fine.
lot of it was good information. some things I came across seemed questionable or outdated. worth keeping tabs on though

like this NASA page has a link to a list of "known black holes"
which gives some details about each of the one listed
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/011120a.html

http://mintaka.sdsu.edu/faculty/orosz/web/

 

[marcus]

survey of cosmology by Padmanabhan

I like Thanu Padmanabhan, he is a worldclass relativist and cosmologist and he uses references to lewis carroll hunting of the snark
and generally manages to be deep and witty some of the time
and he also pulled the rug out from under string theory recently with his paper that says it is not enough for a theory to produce gravitons, that does not make it a quantum gravity theory
he had this paper From Gravitons to Gravity: Myths versus Reality

Well padmanabhhan has come out with one of these surveys of cosmology for general audience, that a senior cosmologist may do every now and then.
http://arxiv.org/abs/gr-qc/0503107
Understanding Our Universe: Current Status and Open Issues
T. Padmanabhan
To appear in "100 Years of Relativity - Space-time Structure: Einstein and Beyond", A.Ashtekar (Editor), World Scientific (Singapore, 2005); 30 pages; 4 figures

"Last couple of decades have been the golden age for cosmology. High quality data confirmed the broad paradigm of standard cosmology but have thrusted upon us a preposterous composition for the universe which defies any simple explanation, thereby posing probably the greatest challenge theoretical physics has ever faced. Several aspects of these developments are critically reviewed, concentrating on conceptual issues and open questions. [Topics discussed include: Cosmological Paradigm, Growth of structures in the universe, Inflation and generation of initial perturbations, Temperature anisotropies of the CMBR, Dark energy, Cosmological Constant, Deeper issues in cosmology.]"

 

[turbo]

WGBH forum with streaming video lectures on LOTS of subjects, including astronomy (under the science subject heading).

http://forum.wgbh.org/wgbh/

 

[marcus]

basic reference on neutron stars

http://arxiv.org/abs/physics/0503245
Neutron Stars
Gordon Baym, Frederick K. Lamb
Comments: Encyclopedia of Physics 3rd ed., R.G. Lerner and G.L. Trigg, eds., Wiley-VCH, Berlin

Abstract: "This short encyclopedia article, reviewing current information on neutron stars, is intended for a broad scientific audience."

Only 3 pages, but has a lot of interesting facts about the topic


Also turbo supplied a link to a Feynman lecture audio on conservation of energy

http://home.hockaday.org/HockadayNet/academic/physics/SciTeach/FeynEng.html

 

[cosmoboy]

hi,
I woould like to suggest the following:

Review articles
1. Large scale structure of the universe and cosmological
perturbation theory (Bernardeau et al)
http://arxiv.org/abs/astro-ph/0112551
2. Cosmological Constant - the Weight of the Vacuum
( T. Padmanabhan)
http://arxiv.org/abs/hep-th/0212290
3. Lagrangian Perturbation and Other Approximations to Nolinear Gravitational Evolution
http://www.columbia.edu/~fms5/w161.html


Books
1.Particle Physics and Inflationary Cosmology
(Andrei Linde)
http://arxiv.org/abs/hep-th/0503203

 

[marcus]

this paper describes a possible test of GR using LISA
Clifford Will is a co-author
http://arxiv.org/abs/gr-qc/0504017

 

[marcus]

A FAQ is what does it mean that the old classical model of BH fails to compute at a certain point (has a "singularity") and gives non-physical answers or no answers at all.

What it means is a fault or limitation of the old classical Gen Rel theory. So now people are studying improved models of BH which don't have that failing. here are some people:

Abhay Ashtekar, Viqar Husain, Oliver Winkler, Leonardo Modesto, Martin Bojowald, Roy Maartens, Rituparno Goswami, Parampreet Singh.

Here are some recent research papers that they have written:

http://arxiv.org/abs/gr-qc/0504029
http://arxiv.org/abs/gr-qc/0503041
http://arxiv.org/abs/gr-qc/0504043
http://arxiv.org/abs/gr-qc/0411032
http://arxiv.org/abs/gr-qc/0407097
http://arxiv.org/abs/gr-qc/0412039
http://arxiv.org/abs/gr-qc/0410125

 

[wolram]

http://www.psychcentral.com/psypsych/Milky_Way

The Milky-way lots of links and info on our backyard.

 

[cosmo_boy]

Use this topic to post links to helpful/informative websites about astronomy & cosmology.

Here you can find many interesting recent papers in
physics & astrophysics.

http://web.mit.edu/redingtn/www/netadv/welcome.html

 

[marcus]

http://chandra.harvard.edu/photo/2002/0192/BH_merge_sm.mov

This an animation of the collision and merger of two galaxies followed by the merger of their central supermassive black holes. the black holes spiral in towards each other ever faster as they loose energy by radiating away gravity waves.

Here is an update of something posted a few times back: a FAQ is what does it mean that the old classical model of BH fails to compute at a certain point (has a "singularity") and gives non-physical answers or no answers at all.

What it means is a fault or limitation of the old classical Gen Rel theory. So now people are studying improved models of BH which don't have that failing. here are some people:

Abhay Ashtekar, Viqar Husain, Oliver Winkler, Leonardo Modesto, Martin Bojowald, Roy Maartens, Rituparno Goswami, Parampreet Singh.

Here are some recent research papers that they have written:
http://www.arxiv.org/abs/gr-qc/0509075 (Ashtekar and Bojowald latest)
http://www.arxiv.org/abs/gr-qc/0509078 (Modesto latests)
http://arxiv.org/abs/gr-qc/0504029
http://arxiv.org/abs/gr-qc/0503041
http://arxiv.org/abs/gr-qc/0504043
http://arxiv.org/abs/gr-qc/0411032
http://arxiv.org/abs/gr-qc/0407097
http://arxiv.org/abs/gr-qc/0412039
http://arxiv.org/abs/gr-qc/0410125

 

[marcus]

H. Rosewater has pointed out that this reference thread has no discussion of what it means to assume the universe is spatially homogeneous and isotropic.
Hellfire gave a pointer to this PF thread:
https://www.physicsforums.com/showthread.php?p=730619#post730619
where hellfire and SpaceTiger supply definitions and some examples are discussed.

I think these are symmetry assumptions-----one knows that the universe is spatially NOT symmetric but is instead fascinatingly different everywhere one looks, but that averaged out at large scale it has approximate symmetry. So for simplicity and convenience one decides to assume perfect translational and rotational symmetry.

That being decided, thereafter whatever functions one uses to describe the universe at some moment in time must have translational symmetry (be unchanged by shifting the origin) and rotational symmetry (be unchanged by rotating the coordinates)

Feel free to expand or clarify. If anyone comes up with a link to some particularly good definition please post it. otherwise, for more discussion see what hellfire and SpaceTiger had to say

 

[marcus]

this might turn out to be a handy reference, it reviews why one usually accepts that things that look like black holes really are that---even though one wants to keep on testing and checking

http://arxiv.org/abs/hep-ph/0511217
Trust but verify: The case for astrophysical black holes
Scott A. Hughes
Based on invited lectures at the 2005 SLAC Summer Institute (SSI05-L006). 22 pages, 5 eps figures
"This article is based on a pair of lectures given at the 2005 SLAC Summer Institute. Our goal is to motivate why most physicists and astrophysicists accept the hypothesis that the most massive, compact objects seen in many astrophysical systems are described by the black hole solutions of general relativity. We describe the nature of the most important black hole solutions, the Schwarzschild and the Kerr solutions. We discuss gravitational collapse and stability in order to motivate why such objects are the most likely outcome of realistic astrophysical collapse processes. Finally, we discuss some of the observations which -- so far at least -- are totally consistent with this viewpoint, and describe planned tests and observations which have the potential to falsify the black hole hypothesis, or sharpen still further the consistency of data with theory."

 

[marcus]

Cosmic neutrino background, why the temperature is less by a factor of 1.401

this is from the Georgia State University knowledge base called "hyperphysics" run by their physics and astronomy department
http://www.phy-astr.gsu.edu/new_web/newmain.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/astro/neutemp.html

 

[marcus]

Some ideas for future tests of General Relativity.
I was intrigued and wanted to keep tabs on this short (4 page) paper:

http://arxiv.org/abs/gr-qc/0610047
Testing General Relativity with Atom Interferometry
Authors: Savas Dimopoulos, Peter W. Graham, Jason M. Hogan, Mark A. Kasevich
4 pages, 1 figure

"The unprecedented precision of atom interferometry will soon lead to laboratory tests of general relativity to levels that will rival or exceed those reached by astrophysical observations. We propose such an experiment that will initially test the equivalence principle to 1 part in 10^15 (300 times better than the current limit), and 1 part in 10^17 in the future. It will also probe general relativistic effects--such as the non-linear three-graviton coupling, the gravity of an atom's kinetic energy, and the falling of light--to several decimals. Further, in contrast to astrophysical observations, laboratory tests can isolate these effects via their different functional dependence on experimental variables."

the authors are all at the Stanford physics department

 

[Garth]

Some ideas for future tests of General Relativity.
I was intrigued and wanted to keep tabs on this short (4 page) paper:

http://arxiv.org/abs/gr-qc/0610047
Testing General Relativity with Atom Interferometry
Authors: Savas Dimopoulos, Peter W. Graham, Jason M. Hogan, Mark A. Kasevich
4 pages, 1 figure

"The unprecedented precision of atom interferometry will soon lead to laboratory tests of general relativity to levels that will rival or exceed those reached by astrophysical observations. We propose such an experiment that will initially test the equivalence principle to 1 part in 10^15 (300 times better than the current limit), and 1 part in 10^17 in the future. It will also probe general relativistic effects--such as the non-linear three-graviton coupling, the gravity of an atom's kinetic energy, and the falling of light--to several decimals. Further, in contrast to astrophysical observations, laboratory tests can isolate these effects via their different functional dependence on experimental variables."

the authors are all at the Stanford physics department

I was interested in this paper too. A test of the EEP to one part in 10¹⁷ would be able to falsify the "Self Creation Cosmology" gravitational theory - but then hopefully GP-B (also Stanford University) will do that anyway before too long! (April 07?)

Garth

 

[Astronuc]

NASA's Astrophysics Science Division Colloquium Series

http://www.universe.nasa.gov/seminars/EUDcolloq/

 

[Astronuc]

This collection may be of interest -

Supernovae and Gamma Ray Bursts
June 21, 2004 - August 27, 2004
http://www.int.washington.edu/talks/WorkShops/int_04_2/

There are a lot more -

http://www.int.washington.edu/talk_list.html

http://www.int.washington.edu/PROGRAMS/programs_all.html

http://www.int.washington.edu/PROGRAMS/past_programs.html

Stellar Abundances & Nucleosynthesis Conference
http://www.int.washington.edu/talks/WorkShops/Stellar/

 

[marcus]

Siobhan Morgan's redshift calculator has a new URL

http://www.uni.edu/morgans/ajjar/Cosmology/cosmos.html

when you start with it, put in three standard parameters
matter density 0.27
Lambda density 0.73
Hubble parameter 71

then it is ready and you can put some redshift like 3 into the "z box"
and it will give you data on light coming to us with that redshift
like travel time
and recession speed when and where the light was emitted
and recession speed of the emitter object now, etc.

 

[Huashan]

This collection may be of interest -

Supernovae and Gamma Ray Bursts
June 21, 2004 - August 27, 2004
http://www.int.washington.edu/talks/WorkShops/int_04_2/

...

Wow ... great!... i suggest everybody to see this ..:!)

thanks ...

 

[marcus]

Good talk given by Roger Penrose at Cambridge on 7 November 2005

http://www.Newton.cam.ac.uk/webseminars/pg+ws/2005/gmr/gmrw04/1107/penrose/

topic was "Before the Big Bang"
and he said that only a couple of months earlier if someone had asked him he would have given the conventional answer that the question didn't make sense and there wasn't any "before"

if we can believe that, which could involve some striving for effect, then as recently as September 2005, Penrose would have said nothing before big bang, undefined.

but apparently now he has changed his mind----likes to talk about ideas of what was before the start of our universe expansion.
I heard him give the same talk in 2006, same slides, at MSRI Berkeley in 2006, and he also gave the talk at Perimeter in 2006.

great thing about this talk is his handdrawn pictures. good cartoonist. helps you understand both cosmology and thermodynamics in a more visual intuitive way
incredible what some people can do with just 3 or 4 different colors of felt-tip pen

 

[Astronuc]

Look for the complete series 'UA: Space University' beginning this Sunday, July 29, both online and in the print edition of the Arizona Daily Star.

http://regulus2.azstarnet.com/mediaskins/main.php?id=1823

Series Preview - UA: Space University
Observers at the University of Arizona's Steward Observatory telescope on Mt. Lemmon search the sky for objects that could collide into Earth. First part is an interview with Stephen Larson.

 

[Astronuc]

This might be of interest to students

ASTC22 Galactic and Extragalactic Astrophysics
http://planets.utsc.utoronto.ca/~pawel/ASTC22/

 

[Astronuc]

Structure and dynamics of the solar chromosphere
Johannes Mattheus Krijger

http://igitur-archive.library.uu.nl/dissertations/2003-0321-121547/inhoud.htm

 

[Astronuc]

The Carnegie-Irvine Nearby Galaxies Survey

Also referenced in some older papers as Carnegie Nearby Galaxy Survey

from http://arxiv.org/PS_cache/astro-ph/pdf/0508/0508338v1.pdf
[10] Mathewson D. S., Ford V. L., Buchhorn M., 1992, ApJS, 81, 413
[11] Persic M., Salucci P., 1995, ApJS, 99, 501

http://www.ociw.edu/%7Elho/projects/CINGS/CINGS.html

http://www.ociw.edu/~lho/projects/CINGS/Survey/index.html

http://www.ociw.edu/~lho/projects/CINGS/Survey/survey.html

Doesn't seem to have been updated in the last 2 years.

But it has photometric properties -
http://www.ociw.edu/~lho/projects/CINGS/Survey/leda2.html

 

[Astronuc]

Ohio State University Bright Spiral Galaxy Survey

http://www.astronomy.ohio-state.edu/~survey/

The goal of the Ohio State Bright Spiral Galaxy Survey is to create a database of deep, photometrically calibrated images of a complete magnitude limited sample of nearly 200 bright, nearby, well-resolved spirals.

Near-IR and Optical Morphology of Spiral Galaxies
http://www.arxiv.org/abs/astro-ph/0206320/

Galaxies from the OSU Spiral Galaxy Survey Master List for which
BVRJHK observations have been completed.
http://www.astronomy.ohio-state.edu/~frogel/OSUgalsurvey/GalaxiesDone.html

http://www.astronomy.ohio-state.edu/~survey/EDR/Data/

 

[Astronuc]

Untwisting the Tornado: X-Ray Imaging and Spectroscopy of G357.7-0.1

report on the detection of X-ray emission from the unusual Galactic radio source G357.7-0.1 (the "Tornado"). Observations made with the Chandra X-Ray Observatory demonstrate the presence of up to three sources of X-ray emission from the Tornado:

http://www.journals.uchicago.edu/ApJ/journal/issues/ApJL/v594n1/17398/17398.html?erFrom=-2587168887994415514Guest

 

[Astronuc]

VLTI - Very Large Telescopic Interferometer

This might be of interest to those involved or seeking opportunities in visual/optical astronomy.

http://www.vlti.org/home.php

http://www.vlti.org/project.php?cid=2

Project Overview
ONTHEFRINGE is a series of four schools designed to train young astronomers in optical interferometry. Optical interferometry is a new technology enabling observations with angular resolution an order of magnitude larger than the largest single telescopes available at visible and infrared wavelengths. Optical interferometry is the only technology allowing the systematic direct detection and characterization of Earthlike planets orbiting other stars. Therefore it plays a key role in ESAs long-range plan through the Darwin mission, and in NASA's Origins program via TPF-I. On the ground Europe has achieved leadership with the ESO Very Large Telescope Interferometer (VLTI). Interferometry from the ground will play a central role in:

• understanding the lifecycles of stars in the Milky Way,
• the discovery and characterization of planets orbiting stars in the solar neighborhood, and
• the understanding of the energy conversion mechanisms in Active Galactic Nuclei.

 

[marcus]

Wallace found this link to the 2005 Lineweaver Davis article in the SciAm called
Misconceptions about the Big Bang.
http://www.astro.princeton.edu/~aes/AST105/Readings/misconceptionsBigBang.pdf

The article used to be available at the SciAm website but I've noticed that what they have there has been dwindling----some very educational graphics have been eliminated---maybe because storage is scarce.

It is a really good article, very helpful. Classic example of general audience hype-free science writing----cool clearheaded no gee-whiz---by a top expert. Much needed because of persistent misunderstanding of the standard world model

The collection that the link came from is worth knowing about
http://www.astro.princeton.edu/~aes/AST105/syllabus.notes.html

this gives the readings for a Princeton general astronomy course (for nonscience majors) no calculus needed.
the course was taught in 2005 by Ostriker and Shapley.
it is a good kind of course that can teach a lot about how we understand and measure the universe just using pictures, high school mathematics like simple algebra and trig, and intuitive verbal description

there are a lot of links to readings here that could be useful to us at PF, as long as they stay live.
information page for the course (Astro 105) is
http://www.astro.princeton.edu/~aes/AST105/course.information.html
which has a link to the homepage at the bottom, if you want

 

[marcus]

To have this handy to refer to,
http://arxiv.org/abs/astro-ph/0603449
Page 50 Figure 17
==quote==
Fig. 17.— Constraints on a non-flat universe with quintessence-like dark energy
with constant w (ModelM10 in Table 3). The contours show the 2-d marginalized
contours for w and Omega_k based on the the CMB+2dFGRS+SDSS+supernova data
sets. This figure shows that with the full combination of data sets, there are
already strong limits on w without the need to assume a flat universe prior.
The marginalized best fit values for the equation of state and curvature are
w = −1.08 ± 0.12 and
Omega_k = −0.026+0.016/−0.015 at the 68% confidence level.
==endquote==

The confidence interval for Omega_k is [-0.041, -0.010]

That means that the confidence interval for Omega_total, or simply Omega, is
[1.010, 1.041]