New species of extremely distant galaxies found emitting only infrared

Scientists Discover Strange New 'Species' of Galaxy Unlike Any Ever Seen
| PCWorld
http://www.pcworld.com/article/24541...ever_seen.html

On 12/4/11 3:30 PM, Yousuf Khan wrote:
Scientists Discover Strange New 'Species' of Galaxy Unlike Any Ever Seen
| PCWorld
http://www.pcworld.com/article/24541...ever_seen.html



Four IRAC Sources with an Extremely Red H-[3.6] Color: Passive or Dusty
Galaxies at z4.5?
http://arxiv.org/abs/1110.4129

"We report detection of four IRAC sources in the GOODS-South field with
an extremely red color of H−[3.6]4.5. The four sources are not detected
in the deep HST WFC3 H-band image with Hlimit=28.3mag. We find that only
3 types of SED templates can produce such a red H−[3.6] color: a very
dusty SED with the Calzetti extinction of A_V =16 mag at z=0.8; a very
dusty SED with the SMC extinction of A_V =8 mag at z=2.0∼2.2; and an
1Gyr SSP with A_V = ∼0.8 at z=5.7. We argue that these sources are
unlikely dusty galaxies at z≤2.2 based on absent strong MIPS 24µm
emission. The old stellar population model at z4.5 remains a possible
solution for the 4 sources. At z4.5, these sources have stellar masses
of Log(M∗/M⊙)=10.6∼11.2. One source, ERS-1, is also a type-II X-ray QSO
with L2−8keV =1.6×10^44 erg s−1. One of the four sources is an X-ray QSO
and another one is a HyperLIRG, suggesting a galaxy-merging scenario for
the formation of these massive galaxies at high redshifts".

See: http://arxiv.org/pdf/1110.4129v1

In article ,
Sam Wormley writes:
See: http://arxiv.org/pdf/1110.4129v1

The CfA press release is at
http://www.cfa.harvard.edu/news/2011/pr201133.html

and the actual published article at
http://iopscience.iop.org/2041-8205/742/1/L13/fulltext/
seems to be publically-readable, at least at the moment.

I don't think -- based on existing data -- I'd have described these
galaxies as a "new species," but they are more extreme than any seen
before. Maybe they will turn out to be something entirely new when
more data are collected, though, or maybe I'm missing something.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

On 05/12/2011 4:09 PM, Steve Willner wrote:
In ,
Sam writes:
See: http://arxiv.org/pdf/1110.4129v1

The CfA press release is at
http://www.cfa.harvard.edu/news/2011/pr201133.html

and the actual published article at
http://iopscience.iop.org/2041-8205/742/1/L13/fulltext/
seems to be publically-readable, at least at the moment.

I don't think -- based on existing data -- I'd have described these
galaxies as a "new species," but they are more extreme than any seen
before. Maybe they will turn out to be something entirely new when
more data are collected, though, or maybe I'm missing something.

I personally thought they are emitting at the Infrared simply because
that's where they have red-shifted to.

Yousuf Khan

On Dec 6, 6:20*am, Yousuf Khan wrote:
On 05/12/2011 4:09 PM, Steve Willner wrote:

In ,
* Sam *writes:
See:http://arxiv.org/pdf/1110.4129v1

The CfA press release is at
*http://www.cfa.harvard.edu/news/2011/pr201133.html

and the actual published article at
*http://iopscience.iop.org/2041-8205/742/1/L13/fulltext/
seems to be publically-readable, at least at the moment.

I don't think -- based on existing data -- I'd have described these
galaxies as a "new species," but they are more extreme than any seen
before. *Maybe they will turn out to be something entirely new when
more data are collected, though, or maybe I'm missing something.

I personally thought they are emitting at the Infrared simply because
that's where they have red-shifted to.

* * * * Yousuf Khan

It's a little of each, although perhaps mostly spent stars and way too
much dust or carbon buckyballs in the way of those deeply reddish and
IR photons.

http://translate.google.com/#
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”