The dark GRB080207 in an extremely red host and the implications for GRBs in highly obscured environments

Details The dark GRB080207 in an extremely red host and the implications for GRBs in highly obscured environments The dark GRB080207 in an extremely red host and the implications for GRBs in highly obscured environments

2011-09-14

arxiv.org/abs/1109.3167v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

13 pages, 6 figures, accepted for publication in MNRAS

Scientific paper

[Abridged] We present comprehensive X-ray, optical, near- and mid-infrared, and sub-mm observations of GRB 080207 and its host galaxy. The afterglow was undetected in the optical and near-IR, implying an optical to X-ray index <0.3, identifying GRB 080207 as a dark burst. Swift X-ray observations show extreme absorption in the host, which is confirmed by the unusually large optical extinction found by modelling the X-ray to nIR afterglow spectral energy distribution. Our Chandra observations obtained 8 days post-burst allow us to place the afterglow on the sky to sub-arcsec accuracy, enabling us to pinpoint an extremely red galaxy (ERO). Follow-up host observations with HST, Spitzer, Gemini, Keck and the James Clerk Maxwell Telescope (JCMT) provide a photometric redshift solution of z ~1.74 (+0.05,-0.06) (1 sigma), 1.56 < z < 2.08 at 2 sigma) for the ERO host, and suggest that it is a massive and morphologically disturbed ultra-luminous infrared galaxy (ULIRG) system, with L_FIR ~ 2.4 x 10^12 L_solar. These results add to the growing evidence that GRBs originating in very red hosts always show some evidence of dust extinction in their afterglows (though the converse is not true -- some extinguished afterglows are found in blue hosts). This indicates that a poorly constrained fraction of GRBs occur in very dusty environments. By comparing the inferred stellar masses, and estimates of the gas phase metallicity in both GRB hosts and sub-mm galaxies we suggest that many GRB hosts, even at z>2 are at lower metallicity than the sub-mm galaxy population, offering a likely explanation for the dearth of sub-mm detected GRB hosts. However, we also show that the dark GRB hosts are systematically more massive than those hosting optically bright events, perhaps implying that previous host samples are severely biased by the exclusion of dark events.

Affiliated with

Also associated with

No associations

Rating

The dark GRB080207 in an extremely red host and the implications for GRBs in highly obscured environments does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The dark GRB080207 in an extremely red host and the implications for GRBs in highly obscured environments, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The dark GRB080207 in an extremely red host and the implications for GRBs in highly obscured environments will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-570359