tag:blogger.com,1999:blog-3612697638678594412.comments2024-02-29T06:27:03.483-07:00CANDELSAnonymoushttp://www.blogger.com/profile/17704873086455232100noreply@blogger.comBlogger58125tag:blogger.com,1999:blog-3612697638678594412.post-82276911668023792182015-09-14T13:13:47.619-07:002015-09-14T13:13:47.619-07:00What a great interview and a promising young scien...What a great interview and a promising young scientist! Anonymoushttps://www.blogger.com/profile/01257470757985186641noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-84533754633352614162014-08-21T16:13:11.940-07:002014-08-21T16:13:11.940-07:00Question? concerning the galactic plane, are there...Question? concerning the galactic plane, are there any signs of alignment or predisposition for alignment of the galactic plane in regards to all the galaxies? thank you and your colleagues for the fantastic research! tyAnonymoushttps://www.blogger.com/profile/11308382158330243874noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-27324084380458869542014-08-01T13:42:58.094-07:002014-08-01T13:42:58.094-07:00And here's another—
Galaxies may have nucleat...And here's another—<br /><br />Galaxies may have nucleated following BBN like water droplets condensing on dust and pollen grains in rain clouds by gravitational compression endothermically driving BBN backwards, promoting nearly isothermal collapse, condensing galaxies from the continuum. And this may have occurred in the early universe when the density of the continuum was on the order of galaxy-scale masses fitting within stellar-scale spaces.<br /><br />Likewise, globular clusters may have condensed within newly-nucleated galaxies during localized endothermic 'helium reionization' (before hydrogen reionization) events, due to gravitational compression.<br /><br />And 'globules' may have condensed within galaxies (and globular clusters) during endothermic reionization of hydrogen caused by gravitational compression, where invisible primordial globules = cold dark matter. Primordial globules contaminated by stellar metallicity in galactic disks become opaque 'Bok globules', and their outgassing in the form of cometary tails and elephant trunks eroded by OB supergiant stars create (giant) molecular clouds.<br /><br />And stars condense within metallicity-contaminated Bok globules during endothermic reionization of hydrogen due to gravitational compression, forming their second hydrostatic cores (Larson 1969).<br /><br />Finally, hot-Jupiter gas-giant planets condense from outer stellar layers of their progenitor stars when their host stars undergo endothermic hydrogen-reionization collapse, forming their second hydrostatic cores.Dave19128https://www.blogger.com/profile/11976361505661383968noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-47931044669808896732014-02-05T01:14:17.067-07:002014-02-05T01:14:17.067-07:00All this data is great. So much accessible to so ...All this data is great. So much accessible to so many. Its like we're in a space race to understand the universe, and we're almost at the finish line. Now we've got to bring that knowledge to the people and help them see what discoveries lie just beneath the surface of popular culture. And then there's all them X-files to be.declassified and packaged into cinematic travelogues or something. Some day we'll get there. <br /><br />All this data posted all over the internet about the universe and planetary discoveries reminds one of the Victorian enlightenment's studies about all the ideas they didn't quite grasp, yet were beginning to finally piece together Somehow all this data must coalesce into some sort of super museum or online mall for all the data models and scientific researchers. There are some of the old guard that resist the currents of the tides of change, yet we are headed in the direction of universal revelation with such a critical mass of data real, change is imminently on the horizon. <br /><br />These are exciting times to be living in, and we should all be grateful to witness all this scientific advance, considering how far we have now advanced, despite the numerous setbacks of the Cold War. <br /><br />It is as if we are about to get off the beach of evolution and back into the garden of divine knowledge. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-30092529707760286932014-02-05T00:51:34.465-07:002014-02-05T00:51:34.465-07:00How long till the point of no return?
How long till the point of no return? <br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-31190683023793899652013-11-20T22:30:41.237-07:002013-11-20T22:30:41.237-07:00Just came across this post while looking for a goo...Just came across this post while looking for a good illustration of how a grism works. Love the illustrations, Ben! Ivahttps://www.blogger.com/profile/10308453488306338594noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-13333381998681625852013-11-20T12:35:13.674-07:002013-11-20T12:35:13.674-07:00Romeel! This is an awesome blog on so many levels...Romeel! This is an awesome blog on so many levels - for the avid professional and the novice. Well done! Prof. Daniel McIntoshhttps://www.blogger.com/profile/12653037038298618248noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-50246528778696396392013-11-18T14:56:51.380-07:002013-11-18T14:56:51.380-07:00Thanks for your comment. For brevity’s sake, and a...Thanks for your comment. For brevity’s sake, and also for the sake of focusing on galaxy evolution, I didn’t get into the possibility of detecting individual merging pairs of black holes. As I’m sure you know, this is possible with pulsar timing arrays as well as with LIGO/Virgo. My point was that if I had to wager how merging pairs of *supermassive* black holes will first be detected, I would bet on the stochastic background over an individual detection. (Ordinary black holes are another story altogether.) But who knows what Nature will actually tell us. As for merging white dwarf pairs, I was giving an example of a GW source that’s outside the detection regime for pulsar timing arrays. What I didn’t say is that the ideal detector for such pairs, the LISA mission (Laser Interferometer Space Antenna) was sadly canceled due to funding limitations. Not wanting to open up this “can of worms”, I suppose I did make it sound like LIGO/Virgo would detect white dwarfs, which of course it’s not designed for.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-65335756073783194322013-11-07T13:23:41.581-07:002013-11-07T13:23:41.581-07:00There are a few misleading statements about the LI...There are a few misleading statements about the LIGO/Virgo source population here. To be detected, a binary system needs to be orbiting with a frequency that the detector is sensitive to (tens to thousands of times per second for LIGO/Virgo). White dwarfs, being much larger than neutron stars or stellar-mass back holes, will collide with each other before they get to orbit that fast. <br /><br />LIGO/Virgo ends up being sensitive to binaries that contain neutron stars or stellar-mass black holes (up to about a hundred solar masses) only in the final seconds before merger, but the advanced versions will be capable of detecting binary systems in distant galaxies (~hundreds of megaparsecs) - which is fortunate, because we don't expect the actual mergers to happen very often in our own galaxy.Jocelynhttps://www.blogger.com/profile/13654426960479129569noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-58724129973766280442013-09-06T12:09:14.016-07:002013-09-06T12:09:14.016-07:00Harry, I'd like to thank you for posting the c...Harry, I'd like to thank you for posting the correction in the Phys.org forum. The licence taken in press releases can do more damage then good in engaging the public and your clarification has gone a long way towards correcting the false impression given.<br /><br />Thank you<br />George<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-69004994905020405192013-08-22T21:17:26.330-07:002013-08-22T21:17:26.330-07:00I think they were mostly (if not all) taken from t...I think they were mostly (if not all) taken from the Hubble Ultra-deep field, which is actually included in the CANDELS "footprint" on the sky, but had a much longer exposure time. The galaxies in the "11 billion year" category in the collage are mostly at redshift z=0.6 to 1 rather than z=2.5 --- so we are seeing light that left 6-8 billion years ago rather than 11 billion years ago. We'll be making a new collage using galaxies at the correct redshifts and will post it on the blog when it's ready.Harry Fergusonhttps://www.blogger.com/profile/02737594514049700386noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-46279265746845066722013-08-21T14:15:09.781-07:002013-08-21T14:15:09.781-07:00Very glad for the correction and explanation. In t...Very glad for the correction and explanation. In the original ESA press release, then, where do the images marked as "11 billion years" old come from, if not from CANDELS observations?Kyle Willetthttps://www.blogger.com/profile/15608184720046638385noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-14521659742537279832013-08-20T13:58:01.053-07:002013-08-20T13:58:01.053-07:00Hooray for Spitzer!!Hooray for Spitzer!!sciencespringshttps://www.blogger.com/profile/03262201473625919137noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-36796429790295883932013-08-19T13:36:15.818-07:002013-08-19T13:36:15.818-07:00Only for the last figure. There the images have be...Only for the last figure. There the images have been resized so that they are the the same physical scale. Harry Fergusonhttps://www.blogger.com/profile/02737594514049700386noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-81212926804600819272013-08-18T16:18:49.413-07:002013-08-18T16:18:49.413-07:00Hi,
Are the images of the galaxies resized so we c...Hi,<br />Are the images of the galaxies resized so we can compare their real sizes with each other in the montage?<br /><br />Thank you and congratulations for the great work.Fernando da Cruzhttps://www.blogger.com/profile/06227315674459209797noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-67778862232414531342013-07-27T00:43:47.930-07:002013-07-27T00:43:47.930-07:00Nice analogy of the BH throwing a "tantrum&qu...Nice analogy of the BH throwing a "tantrum". But when you say that you don't see any evidence of tantrums in the majority of AGN, then you might be biased, because you are only looking at certain AGN. Keeping with the tantrum analogy - when we look at a certain population of humans throwing tantrums, most of the adult population does not (there are some adults that do, but most don't). But if you look at 2 year olds, then your odds of finding "tantrums" increases. Similarly, you should look at YOUNG AGN, that have high accretion rates, typically found in IR-selected AGN and your fraction of "feedbacking AGN" increases dramatically - see e.g. the ULIRG results of Herschel's large AGN driven molecular outflows.<br /><br />However, I do agree we need to find whether M-sigma is really causal at all! This is very important!bellatrix78https://www.blogger.com/profile/17286560853976919039noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-40532998555903997242013-07-19T12:16:25.475-07:002013-07-19T12:16:25.475-07:00M87 is mine!!!!!! :PM87 is mine!!!!!! :PAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-81636595512297621772013-03-22T11:26:04.358-07:002013-03-22T11:26:04.358-07:00A few refinements, after hearing a very nice summa...A few refinements, after hearing a very nice summary of the results by Marc Kamionkowski at Johns Hopkins. <br /><br />First, it's probably wrong to say "the universe is expanding more slowly than we thought." Instead I should have said that the expansion rate estimated from the CMB disagrees with the more direct measurements in the nearby universe. One possible solution is that Dark Energy makes the change in the expansion rate different than the simplest model (in technical terms, the equation of state parameter w might be less than the simplest assumption w=-1). If that interpretation were confirmed it would be a profound discovery. <br /><br />Second, I was confused about the lopsidedness. The measurement of lopsidedness is in the "total power" of the fluctuations, rather than in the "mean temperature." In other words, the difference between the troughs and valleys on the right-hand side of the map is slightly bigger than on the left side of the map. So the explanation that our galaxy might be moving faster in one direction than previously thought is not viable. I expect there are theorists hard at work already trying to come up with simple explanations. <br /><br />Third, Marc was very excited about the implications for inflationary models (used to explain the first tiny fraction of a second of the expansion of the universe). The relative power of fluctuations on different scales was set in place as the universe emerged from its "exponential expansion" phase, so by getting this snapshot of the relative power you can (a) get a lot more confidence that inflation really happened, and (b) actually say something about this transition phase.Harry Fergusonhttps://www.blogger.com/profile/02737594514049700386noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-1509964769624109342013-01-22T09:16:12.917-07:002013-01-22T09:16:12.917-07:00Nice post! The fellow astronomer's joke was fu...Nice post! The fellow astronomer's joke was funny, but not entirely correct, we do not fly out on spheres, but rather in circles (also not quite, but at least it's a better approximation), so it should really be 1/r, I think.Marcelnoreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-12229352717408471222012-12-10T07:30:31.414-07:002012-12-10T07:30:31.414-07:00There is a great deal of discussion back and forth...There is a great deal of discussion back and forth on this. As someone who studies galaxies but not AGN specifically (so a semi-outsider) my synthesis of the situation right now is that it seems that there is a relationship between merging and very active (sometimes dust obscured) accretion (e.g., big quasars; from the e.g., PG quasar studies [Bahcall?] or SWIFT studies [Koss et al.]). At lower accretion luminosities (e.g., Seyfert luminosities), most studies (including CANDELS) are finding weak or no evidence for merger enhancement of AGN activity. Eric Bellhttps://www.blogger.com/profile/05510409701570250287noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-25792989940674268842012-11-15T23:05:01.633-07:002012-11-15T23:05:01.633-07:00Well, this is my first visit to your blog! But I a...Well, this is my first visit to your blog! But I admire the precious time and effort you put into it, especially into interesting articles you share here! <a href="http://petitto.gallaudet.edu" rel="nofollow">fNIRS</a> <br /> Anonymoushttps://www.blogger.com/profile/04713993400084806512noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-27877811591480526362012-11-05T11:15:18.621-07:002012-11-05T11:15:18.621-07:00What I love about this blog is the posts written b...What I love about this blog is the posts written by the astronomers sharing their career insights. Great stories.astrojuandahttps://www.blogger.com/profile/14859117094350934085noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-7590569808684238492012-11-05T11:13:49.619-07:002012-11-05T11:13:49.619-07:00Thanks a lot for sharing your experiences.Thanks a lot for sharing your experiences.astrojuandahttps://www.blogger.com/profile/14859117094350934085noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-72436337235953498722012-10-30T10:52:31.006-07:002012-10-30T10:52:31.006-07:00Nice blog Christina. A big hug from Chile!
Juan C...Nice blog Christina. A big hug from Chile!<br /><br />Juan Cortes Anonymoushttps://www.blogger.com/profile/15416253148590104857noreply@blogger.comtag:blogger.com,1999:blog-3612697638678594412.post-39038589725103918932012-10-24T13:29:06.604-07:002012-10-24T13:29:06.604-07:00Thanks Daniel! A waiting list is an interesting id...Thanks Daniel! A waiting list is an interesting idea. This probably isn't used simply because the field is quickly changing. A proposal might be ranked highly one time but the next time around there may be other more exciting projects to consider. Plus, the original proposer might think of ways to improve upon their initial idea. It does help to keep things moving forward.Jeyhan Kartaltepehttps://www.blogger.com/profile/14875207901031096991noreply@blogger.com