Searching for the first stars with the Gaia mission

Author(s)

de Souza, R. S. ^{[1, 2, 3]} ; Krone-Martins, A. ^[4] ; Ishida, E. E. O. ^{[1, 2]} ; Ciardi, B. ^[2]

Affiliation

^[1] Univ Sao Paulo, IAG, BR-05508900 Sao Paulo - Brazil

^[2] Max Planck Inst Astrophys, D-85748 Garching - Germany

^[3] Korea Astron & Space Sci Inst, Taejon 305348 - South Korea

^[4] Univ Lisbon, Fac Ciencias, SIM, P-1749016 Lisbon - Portugal

• Document type: Journal article
• Source: Astronomy & Astrophysics; v. 545, SEP 2012.
• Web of Science Citations: 7

Abstract

Aims. We construct a theoretical model to predict the number of orphan afterglows (OA) from gamma-ray bursts (GRBs) triggered by primordial metal-free (Pop III) stars expected to be observed by the Gaia mission. In particular, we consider primordial metal-free stars that were affected by radiation from other stars (Pop III. 2) as a possible target. Methods. We use a semi-analytical approach that includes all relevant feedback effects to construct cosmic star formation history and its connection with the cumulative number of GRBs. The OA events are generated using the Monte Carlo method, and realistic simulations of Gaia's scanning law are performed to derive the observation probability expectation. Results. We show that Gaia can observe up to 2.28 +/- 0.88 off-axis afterglows and 2.78 +/- 1.41 on-axis during the five-year nominal mission. This implies that a nonnegligible percentage of afterglows that may be observed by Gaia (similar to 10%) could have Pop III stars as progenitors. (AU)

• FAPESP's process: 11/09525-3 - Analysis of type IA supernovae in wide-field galaxy surveys
• Grantee: Emille Eugenia de Oliveira Ishida
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 09/05176-4 - Analysis of the influence of magnetic fields and cold dark matter in the formation and evolution of galaxies
• Grantee: Rafael da Silva de Souza
• Support Opportunities: Scholarships in Brazil - Post-Doctoral