Thoene 2007 grb 060505的宿主星系

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文章信息:
Spatially resolved properties of the GRB 060505 host: implications for the nature of the progenitor

Authors: Christina C. Thoene, Johan P. U. Fynbo, Goeran Oestlin, Bo Milvang-Jensen, Klaas Wiersema, Daniele Malesani, Desiree Della Monica Ferreira, Javier Gorosabel, D. Alexander Kann, Darach Watson, Michal J. Michalowski, Jens Hjorth, Andrew S. Fruchter, Jesper Sollerman

(Submitted on 15 Mar 2007 (v1), last revised 16 Mar 2007 (this version, v2))

Abstract: GRB 060505 was the first well-observed nearby long-duration GRB that had no associated supernova. Here we present spatially resolved spectra of the host galaxy of GRB 060505, an Sbc spiral, at redshift z=0.0889. The GRB occurred inside a star-forming region in the northern spiral arm at 6.5 kpc from the center. From the position of the emission lines, we determine a maximum rotational velocity for the galaxy of v ~ 212 km/s corresponding to a mass of 1.3x10^11 M_solar within 24 kpc. The Halpha equivalent width at the GRB site gives a very young age of <~ 7 Myr. By fitting single-age spectral synthesis models to the stellar continuum, we derive ages for the dominant stellar populations in different parts of the galaxy resulting in ~ 800 Myr for the bulge an only ~ 47 Myr for the GRB site. The metallicity derived from the R_23 parameter is lowest at the GRB site with 0.14 Z_solar but roughly solar in the rest of the galaxy. The extinction in the galaxy is overall low with A_V < z="0.0896.">

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11 pages, 6 figures, submitted to ApJ; replacement: errors in headings and references corrected, Fig 5a and b switched

Subjects:

Astrophysics (astro-ph)

Cite as:

arXiv:astro-ph/0703407v2