html5-img
1 / 17

Edo Berger Harvard University

The Host Galaxies of High-Redshift GRBs. Edo Berger Harvard University. Outline. 1. GRBs at z<1: Is there a low-metallicity bias?. 2. The ISM of high-redshift galaxies. 3. DLA counterparts & the M-Z relation at z>2. Spitzer stack. Long GRBs Hosts: Metallicity?. metallicity.

palma
Télécharger la présentation

Edo Berger Harvard University

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Host Galaxies of High-Redshift GRBs Edo Berger Harvard University

  2. Outline 1.GRBs at z<1: Is there a low-metallicity bias? 2.The ISM of high-redshift galaxies 3.DLA counterparts & the M-Z relation at z>2 Spitzer stack

  3. Long GRBs Hosts: Metallicity? metallicity redshift mass Levesque, Berger, & Kewley 2009,2010 Low-Z “preference” at z<1; essentially disappears by z~2 Wainwright, EB & Penprase 2007, ApJ

  4. GRB Absorption Spectroscopy QSOs act as background sources of illumination; GRBs are embedded within their host galaxies 40 kpc

  5. GRB Absorption Spectroscopy QSOs act as background sources of illumination; GRBs are embedded within their host galaxies • GRBs vs. quasars: • Small impact parameter • No Mpc proximity effect • In star forming regions • High(er) redshift • Power law spectrum • Fade away 40 kpc

  6. GRB Absorption Spectroscopy Intrinsic Ly series absorption Lyα forest Metals log NH =22.1±0.1 [S/H] = 0.06 Z⦿ Berger et al. 2006

  7. GRB-DLAs 〈ZGRB〉~ 3 x〈ZQSO〉 MW GMCs Berger et al. 2006; Prochaska et al. 2007; Savaglio et al. 2007 Berger et al. 2006; Fynbo et al. 2009 〈N(HI)GRB〉~ 10 x〈N(HI)QSO〉 Complication for reionization? Avi’s question

  8. QSO-DLA Counterparts DLA? HST/NICMOS: H=22 mag; 1/22 detected HST/NICMOS: H=23 mag; confused QSO Colbert & Malkan 2002 Warren et al. 2001

  9. GRB-DLA Counterparts 1. GRBs have <1″ offset: No ambiguity about the identity of the DLA counterpart 2. GRBs fade away: Counterpart can be imaged to L≪ L* regardless of PSF

  10. GRB-DLA Counterparts HST/ACS 1″=1.75 kpc Vreeswijk et al. 2004 Wainwright, Berger, & Penprase 2007 z = 3.372 • F606W(AB) = 28.1 mag • L ≈ 0.02 L* • SFR ≈ 1 M⊙/yr

  11. GRB-DLA Counterparts GRB 050904: z = 6.295 L < L* SFR < 6 M⊙/yr M < 109 M⊙ Berger et al. 2007

  12. GRB-DLA Counterparts Spitzer/IRAC: z ~ 2 - 3 Spitzer/IRAC: z ~ 3 - 5 Chary, Berger, & Cowie 2007 Laskar, Berger, & Chary 2010

  13. GRB-DLA Counterparts GOODS z~1 GRBs Chary, Berger, & Cowie 2007

  14. The M-Z & L-Z Relations at z > 2 z ~ 4 z ~ 4 Chary, Berger, & Cowie 2007 z ~ 0: Tremonti et al. 2004 z ~ 1: Kobulnicky & Kewley 2004; Savaglio et al. 2005 z ~ 2: Erb et al. 2006

  15. The Host of GRB090423 @ z=8.2 Detection at 3.6 m 46 days after the burst (5 days in the rest-frame): 72 hr exposure: 27.2 AB mag = 48 nJy 2nd epoch in 2/2010 to detect the underlying host galaxy, and … No Detection: L < 0.1 L* Chary, Berger, et al. 2009

  16. Obscured Star Formation? z~1-2: SFR ~ 100−300 M⊙/yr LFIR ~ 1012 L⊙ ALMA/EVLA: detections to z~4-6; e.g. correlation of CO & Z

  17. Conclusions • GRBs are a powerful probe of the ISM of high-z galaxies, at redshifts that cannot be currently probed by direct spectroscopic observations • The environments probed by GRBs have higher neutral hydrogen and metal columns than those probed by quasars: probes of star forming regions • Host galaxy observations will soon provide the first M-Z and L-Z relations at z > 2, as well as a mass function of DLAs

More Related