The UvA-LINKER will give you a range of other options to find the full text of a publication (including a direct link to the full-text if it is located on another database on the internet).
De UvA-LINKER biedt mogelijkheden om een publicatie elders te vinden (inclusief een directe link naar de publicatie online als deze beschikbaar is in een database op het internet).


Zoekopdracht: journal id: "astrophysicalxjournal"

AuteursN.R. Tanvir, A.J. Levan, A.S. Fruchter, J.P.U. Fynbo, J. Hjorth, K. Wiersema, M.N. Bremer, J. Rhoads, P. Jakobsson, P.T. O'Brien, E.R. Stanway, D. Bersier, P. Natarajan, J. Greiner, D. Watson, A. Castro-Tirado, R.A.M.J. Wijers, R.L.C. Starling, K. Misra, J.F. Graham, C. Kouveliotou
TitelStar Formation in the Early Universe: Beyond the Tip of the Iceberg
TijdschriftAstrophysical Journal
FaculteitFaculteit der Natuurwetenschappen, Wiskunde en Informatica
Instituut/afd.FNWI: Astronomical Institute Anton Pannekoek (IAP)
SamenvattingWe present late-time Hubble Space Telescope (HST) imaging of the fields of six Swift gamma-ray bursts (GRBs) lying at 5.0 lsim z lsim 9.5. Our data include very deep observations of the field of the most distant spectroscopically confirmed burst, GRB 090423, at z = 8.2. Using the precise positions afforded by their afterglows, we can place stringent limits on the luminosities of their host galaxies. In one case, that of GRB 060522 at z = 5.11, there is a marginal excess of flux close to the GRB position which may be a detection of a host at a magnitude J AB ≈ 28.5. None of the others are significantly detected, meaning that all the hosts lie below L* at their respective redshifts, with star formation rates (SFRs) lsim 4 M ☉ yr–1 in all cases. Indeed, stacking the five fields with WFC3-IR data, we conclude a mean SFR <0.17 M ☉ yr–1 per galaxy. These results support the proposition that the bulk of star formation, and hence integrated UV luminosity, at high redshifts arises in galaxies below the detection limits of deep-field observations. Making the reasonable assumption that GRB rate is proportional to UV luminosity at early times allows us to compare our limits with expectations based on galaxy luminosity functions (LFs) derived from the Hubble Ultra-Deep Field and other deep fields. We infer that an LF, which is evolving rapidly toward steeper faint-end slope (α) and decreasing characteristic luminosity (L*), as suggested by some other studies, is consistent with our observations, whereas a non-evolving LF shape is ruled out at gsim 90% confidence. Although it is not yet possible to make stronger statements, in the future, with larger samples and a fuller understanding of the conditions required for GRB production, studies like this hold great potential for probing the nature of star formation, the shape of the galaxy LF, and the supply of ionizing photons in the early universe.
Soort documentArtikel
Document finderUvA-Linker