48 posts · 22,558 views
I'm a science writer interested in most fields of science, and exploring how to make better use of the online environment for providing scientific information to a curious, engaged, but not specialized audience.
Sort by Latest Post, Most Popular
View by Condensed, Full
- January 30, 2012
- 02:30 AM
- 65 views
How large were the first stars in the universe?
by Charles Daney in Today's Science
Since it is currently, and for the foreseeable future, not possible to actually observe what the first stars in the universe were like when they formed, the only way to answer this question is by detailed calculations from first principles. In other words, by computer simulations. Until very recently, such simulations couldn’t be very conclusive, [...]... Read more »
Hosokawa, T., Omukai, K., Yoshida, N., & Yorke, H. (2011) Protostellar Feedback Halts the Growth of the First Stars in the Universe. Science, 334(6060), 1250-1253. DOI: 10.1126/science.1207433
- January 7, 2012
- 08:45 PM
- 102 views
A hyperactive young galaxy
by Charles Daney in Today's Science
Active galaxies contain a supermassive black hole (SMBH) that causes vigorous radiation of electromagnetic energy as a result of rapid accretion of gas and dust. While almost all galaxies except dwarfs contain an SMBH in the center, active galaxies are rare – fewer that 1% of galaxies in the present universe. A very few active [...]... Read more »
Schawinski, K., Urry, M., Treister, E., Simmons, B., Natarajan, P., & Glikman, E. (2011) EVIDENCE FOR THREE ACCRETING BLACK HOLES IN A GALAXY AT z~1.35: A SNAPSHOT OF RECENTLY FORMED BLACK HOLE SEEDS? . The Astrophysical Journal, 743(2). DOI: 10.1088/2041-8205/743/2/L37
- January 5, 2012
- 01:30 AM
- 93 views
Some supermassive black holes are much more super than others
by Charles Daney in Today's Science
Supermassive black holes (SMBHs) can get to be pretty large. Astrophysicists don’t really know what the upper limit is, if any. But before some recent research, the mass of the largest SMBH yet determined was 6.3×109 M⊙ (solar masses). That value is known fairly precisely, since the SMBH is in the nearby giant elliptical galaxy [...]... Read more »
McConnell, N., Ma, C., Gebhardt, K., Wright, S., Murphy, J., Lauer, T., Graham, J., & Richstone, D. (2011) Two ten-billion-solar-mass black holes at the centres of giant elliptical galaxies. Nature, 480(7376), 215-218. DOI: 10.1038/nature10636
- December 23, 2011
- 07:04 PM
- 132 views
Cosmic rays from stellar superbubbles
by Charles Daney in Today's Science
Cosmic rays were discovered almost 100 years ago (1912), yet astrophysicists are still uncertain about where they come from or how they acquire their extremely high energies. Research recently published gives strong evidence that the Cygnus X region, which contains hundreds of very hot, massive, young stars, is a source of cosmic rays and has [...]... Read more »
Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Belfiore, A., Bellazzini, R., Berenji, B.... (2011) A Cocoon of Freshly Accelerated Cosmic Rays Detected by Fermi in the Cygnus Superbubble. Science, 334(6059), 1103-1107. DOI: 10.1126/science.1210311
- December 19, 2011
- 06:30 PM
- 203 views
Possible constraints on dark matter particle mass
by Charles Daney in Today's Science
Although there is very good indirect evidence for the existence of dark matter, it’s an understatement to say that actual detection of dark matter particles has not been easy. Recent research results from two different teams that both studied gamma rays from dwarf galaxy neighbors of the Milky Way provide an illustration of the difficulty. [...]... Read more »
Geringer-Sameth, A., & Koushiappas, S. (2011) Exclusion of Canonical Weakly Interacting Massive Particles by Joint Analysis of Milky Way Dwarf Galaxies with Data from the Fermi Gamma-Ray Space Telescope. Physical Review Letters, 107(24). DOI: 10.1103/PhysRevLett.107.241303
Ackermann, M., Ajello, M., Albert, A., Atwood, W., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R.... (2011) Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope. Physical Review Letters, 107(24). DOI: 10.1103/PhysRevLett.107.241302
- December 11, 2011
- 11:55 PM
- 337 views
Active star-forming galaxies have substantial halos
by Charles Daney in Today's Science
Detailed new research shows that there is a distinct correlation between galaxies with large, oxygen-rich gas halos and active ongoing star formation. Although active star formation requires large amounts of available gas, what is surprising is that much, or perhaps even most, of the gas may be in the halo region outside of where most [...]... Read more »
Tumlinson, J., Thom, C., Werk, J., Prochaska, J., Tripp, T., Weinberg, D., Peeples, M., O'Meara, J., Oppenheimer, B., Meiring, J.... (2011) The Large, Oxygen-Rich Halos of Star-Forming Galaxies Are a Major Reservoir of Galactic Metals. Science, 334(6058), 948-952. DOI: 10.1126/science.1209840
- December 4, 2011
- 11:30 PM
- 116 views
Cygnus X-1 mass and spin determined
by Charles Daney in Today's Science
Cygnus X-1 was a very puzzling object when it was discovered in 1964, because (as the name suggests) it was an extremely powerful X-ray source. Since X-rays are (fortunately) blocked by the Earth’s atmosphere, the exceptional nature of the object was only recognized when it became possible to do astronomy from above the atmosphere, in [...]... Read more »
Reid, M., McClintock, J., Narayan, R., Gou, L., Remillard, R., & Orosz, J. (2011) THE TRIGONOMETRIC PARALLAX OF CYGNUS X-1. The Astrophysical Journal, 742(2), 83. DOI: 10.1088/0004-637X/742/2/83
Orosz, J., McClintock, J., Aufdenberg, J., Remillard, R., Reid, M., Narayan, R., & Gou, L. (2011) THE MASS OF THE BLACK HOLE IN CYGNUS X-1. The Astrophysical Journal, 742(2), 84. DOI: 10.1088/0004-637X/742/2/84
Gou, L., McClintock, J., Reid, M., Orosz, J., Steiner, J., Narayan, R., Xiang, J., Remillard, R., Arnaud, K., & Davis, S. (2011) THE EXTREME SPIN OF THE BLACK HOLE IN CYGNUS X-1. The Astrophysical Journal, 742(2), 85. DOI: 10.1088/0004-637X/742/2/85
- December 3, 2011
- 01:37 AM
- 144 views
Star formation and molecular clouds in the Large Magellanic Cloud
by Charles Daney in Today's Science
The Large Magellanic Cloud (LMC) is the largest close neighbor of our own galaxy, at a distance of only 160,000 light-years – less than twice the diameter of the Milky Way itself. Its proximity makes it a very useful object to study in connection with the process of star formation, which is generally assumed to [...]... Read more »
Wong, T., Hughes, A., Ott, J., Muller, E., Pineda, J., Bernard, J., Chu, Y., Fukui, Y., Gruendl, R., Henkel, C.... (2011) THE MAGELLANIC MOPRA ASSESSMENT (MAGMA). I. THE MOLECULAR CLOUD POPULATION OF THE LARGE MAGELLANIC CLOUD. The Astrophysical Journal Supplement Series, 197(2), 16. DOI: 10.1088/0067-0049/197/2/16
- December 1, 2011
- 11:19 PM
- 155 views
Magnetic fields may set the stage for birth of new stars
by Charles Daney in Today's Science
Star formation does not happen as easily as one might suppose from the abundance of stars in a galaxy like the Milky Way, in which more than 100 billion times the mass of the Sun (M⊙) exists in the form of stars. Stars condense out of interstellar gas within the galaxy, but the process is [...]... Read more »
Li, H., & Henning, T. (2011) The alignment of molecular cloud magnetic fields with the spiral arms in M33. Nature, 479(7374), 499-501. DOI: 10.1038/nature10551
- November 22, 2011
- 01:00 AM
- 147 views
Neutron star research points to different classes of supernovae
by Charles Daney in Today's Science
Classifying things is the starting point for almost all scientific fields – from flowers to fundamental particles. Once one has classes the next step is to find subclasses, and then sub-subclasses. Finding correlations between different classification schemes, then, often leads to significant understandings. Neutron stars are not stars in the normal sense. They are remnants [...]... Read more »
Knigge, C., Coe, M., & Podsiadlowski, P. (2011) Two populations of X-ray pulsars produced by two types of supernova. Nature, 479(7373), 372-375. DOI: 10.1038/nature10529
- November 11, 2011
- 11:00 PM
- 224 views
Galaxy interactions accelerate the growth of supermassive black holes
by Charles Daney in Today's Science
It’s now well-known that there’s a rough correlation between a galaxy’s size and the size of its central supermassive black hole (SMBH). The correlation is even better (for spiral galaxies) between the black hole size and the size of the central bulge of the galaxy. It’s been found that the mass of a SMBH is [...]... Read more »
J. D. Silverman, P. Kampczyk, K. Jahnke, R. Andrae, S. Lilly, M. Elvis, F. Civano, V. Mainieri, C. Vignali, G. Zamorani.... (2011) The impact of galaxy interactions on AGN activity in zCOSMOS. Astrophysical Journal. arXiv: 1109.1292v1
- November 8, 2011
- 11:30 PM
- 186 views
Hubble directly observes the disk around a black hole
by Charles Daney in Today's Science
Quasars are the brightest persistent objects in the universe. They represent the brightest examples of a somewhat more common object: an active galactic nucleus (AGN). As the name implies, an AGN exists at the center of some galaxies. Most quasars, and even most AGN, are not found in the nearby universe, since they are especially [...]... Read more »
Muñoz, J., Mediavilla, E., Kochanek, C., Falco, E., & Mosquera, A. (2011) A STUDY OF GRAVITATIONAL LENS CHROMATICITY WITH THE HUBBLE SPACE TELESCOPE . The Astrophysical Journal, 742(2), 67. DOI: 10.1088/0004-637X/742/2/67
- November 5, 2011
- 12:43 AM
- 200 views
Record-breaking gamma-ray emissions from a millisecond pulsar
by Charles Daney in Today's Science
Breaking old records for some statistic or another generally makes for catchy headlines, at least. If nothing else, the fact that the statistic is being tracked (whether or not by Guinness) suggests it’s a matter of more than passing interest. Now astrophysicists have come up with a new find that breaks three records at the [...]... Read more »
, ., Freire, P., Abdo, A., Ajello, M., Allafort, A., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R.... (2011) Fermi Detection of a Luminous γ-Ray Pulsar in a Globular Cluster. Science. DOI: 10.1126/science.1207141
- October 30, 2011
- 04:39 AM
- 214 views
Astronomers Pin Down Galaxy Collision Rate
by Charles Daney in Today's Science
Galaxies have been growing over most of the 13.7 billion year history of the universe. Some of the growth is due to intergalactic gas gradually swept up by an existing galaxy and then driving star formation in the galaxy. But another growth mechanism is the merger of two (and sometimes more) existing galaxies into one. [...]... Read more »
Jennifer M. Lotz, Patrik Jonsson, T. J. Cox, Darren Croton, Joel R. Primack, Rachel S. Somerville, & Kyle Stewart. (2011) The Major and Minor Galaxy Merger Rates at z . Astrophysical Journal. arXiv: 1108.2508v1
- October 20, 2011
- 06:30 PM
- 161 views
Distant Galaxies Reveal The Clearing of the Cosmic Fog
by Charles Daney in Today's Science
The first billion years after the big bang (out of about 13.7 billion years total since then) were among the most interesting in terms of giving birth to the kind of objects that still dominate the scene today. Mostly that means stars and galaxies, plus a few exotica such as quasars. Unfortunately, it’s very difficult [...]... Read more »
L. Pentericci, A. Fontana, E. Vanzella, M. Castellano, A. Grazian, M. Dijkstra, K. Boutsia, S. Cristiani, M. Dickinson, E. Giallongo.... (2011) Spectroscopic confirmation of z~7 LBGs: probing the earliest galaxies and the epoch of reionization. Astrophysical Journal. arXiv: 1107.1376v1
- October 17, 2011
- 05:25 PM
- 215 views
Universe’s “Standard Candles” Are White Dwarf Mergers
by Charles Daney in Today's Science
Supernovae are spectacular but fairly rare events, at least on the human time scale. In our own galaxy, only 5 have been seen (necessarily by the naked eye, before telescopes were invented in 1608) in the last 2000 years. Since there have been none in our galaxy when any telescopes were available to study them, [...]... Read more »
Graur, O., Poznanski, D., Maoz, D., Yasuda, N., Totani, T., Fukugita, M., Filippenko, A., Foley, R., Silverman, J., Gal-Yam, A.... (2011) Supernovae in the Subaru Deep Field: the rate and delay-time distribution of Type Ia supernovae out to redshift 2. Monthly Notices of the Royal Astronomical Society, 417(2), 916-940. DOI: 10.1111/j.1365-2966.2011.19287.x
- October 11, 2011
- 08:10 PM
- 195 views
A subluminous, normal-width lightcurve Type Ia supernova in the middle of nowhere
by Charles Daney in Today's Science
Astrophysicists have gradually been refining a system of classification for supernovae. The most basic characteristic of interest is whether or not there are spectral lines that indicate the presence of hydrogen. If these lines are absent, the supernova is Type I, which implies the progenitor star was rather old and had used up all of [...]... Read more »
Maguire, K., Sullivan, M., Thomas, R., Nugent, P., Howell, D., Gal-Yam, A., Arcavi, I., Ben-Ami, S., Blake, S., Botyanszki, J.... (2011) PTF10ops - a subluminous, normal-width light curve Type Ia supernova in the middle of nowhere. Monthly Notices of the Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2011.19526.x
- October 5, 2011
- 11:02 PM
- 191 views
Galaxy Clusters Validate Einstein’s Theory – and Dark Matter Too
by Charles Daney in Today's Science
The theory of relativity – both special relativity and general relativity – has now been tested successfully so many ways ever since its early days that further tests seem almost redundant. (That little mix-up with superluminal neutrinos to the contrary notwithstanding – since it’s at most a higher order correction, but more likely an error [...]... Read more »
Wojtak, R., Hansen, S., & Hjorth, J. (2011) Gravitational redshift of galaxies in clusters as predicted by general relativity. Nature, 477(7366), 567-569. DOI: 10.1038/nature10445
- February 27, 2011
- 10:26 PM
- 329 views
Telomerase can reverse the aging process... sort of
by Charles Daney in Science and Reason
Biologists are, at long last, beginning to understand the molecular processes responsible for aging in complex (multicellular) organisms – and to investigate ways to counteract these processes. We discussed one line of research in this recent article about a particular sirtuin (SIRT3) that helps relieve oxidative stress that can lead to DNA damage, which generally leads, in turn, to cell senescence or death.While oxidative stress is certainly a significant factor in aging, possibly the mos........ Read more »
Jaskelioff, M., Muller, F., Paik, J., Thomas, E., Jiang, S., Adams, A., Sahin, E., Kost-Alimova, M., Protopopov, A., Cadiñanos, J.... (2010) Telomerase reactivation reverses tissue degeneration in aged telomerase-deficient mice. Nature, 469(7328), 102-106. DOI: 10.1038/nature09603
- February 20, 2011
- 11:40 PM
- 566 views
Supermassive black hole in a dwarf galaxy
by Charles Daney in Science and Reason
Supermassive black hole in a type of galaxy where nobody expected to find one? Henize 2-10 is a small, mostly unremarkable compact dwarf galaxy. Its estimated dynamical mass is about 1010 M⊙, only a few percent of our galaxy's mass, and its distance from us is about 30 million light years. It is irregular in shape and does not fit in any category of the standard Hubble sequence.The only respect in which Henize 2-10 has attracted attention – for several decades – before now is a........ Read more »
Reines, A., Sivakoff, G., Johnson, K., & Brogan, C. (2011) An actively accreting massive black hole in the dwarf starburst galaxy Henize 2-10. Nature, 470(7332), 66-68. DOI: 10.1038/nature09724
topics
join us!
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
