Query : 2009A&A...496..381H

2009A&A...496..381H - Astronomy and Astrophysics, volume 496, 381-387 (2009/3-3)

A forming, dust-enshrouded disk at z = 0.43: the first example of a massive, late-type spiral rebuilt after a major merger?


Abstract (from CDS):

By combining Ultra Deep Field imagery from HST/ACS with kinematics from VLT/GIRAFFE, we derive a physical model of distant galaxies in a way similar to that achievable for nearby galaxies. A significant part of the evolution in the density of cosmic star formation is related to the rapid evolution of both luminous IR galaxies (LIRGs) and Luminous Compact galaxies: here we study the properties of a distant, compact galaxy, J033245.11-274724.0, which is also a LIRG. Given the photometric and spectrophotometric accuracies of data of all wavelengths, we can decompose the galaxy into sub-components and correct them for reddening. Combination of deep imagery and kinematics provides a reasonable physical model of the galaxy. The galaxy is dominated by a dust-enshrouded disk revealed by UDF imagery. The disk radius is half that of the Milky Way and the galaxy forms stars at a rate of 20M/yr. Morphology and kinematics show that both gas and stars spiral inwards rapidly to feed the disk and the central regions. A combined system of a bar and two nonrotating spiral arms regulates the material accretion, induces high velocity dispersions, with σ larger than 100km/s and redistributes the angular momentum. The detailed physical properties of J033245.11-274724.0 resemble the expectations of modeling the merger of two equal-mass, gaseous-rich galaxies, 0.5Gyr after the merger. They cannot be reproduced by any combination of intrinsic disk perturbations alone, given the absence of any significant outflow mechanisms. In its later evolution, J033245.11-274724.0 could become a massive, late-type spiral that evolves to become part of the Tully-Fisher relation, with an angular momentum induced mostly by the orbital angular-momentum of the merger.

Abstract Copyright:

Journal keyword(s): galaxies: formation - galaxies: spiral - Galaxy: kinematics and dynamics

Simbad objects: 4

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Number of rows : 4
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
1 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 12376 1
2 NAME Hubble Ultra Deep Field reg 03 32 39.0 -27 47 29           ~ 1599 0
3 CXOCDFS J033245.2-274724 EmG 03 32 45.107 -27 47 24.01 23.3276 22.7276 21.53 21.053 20.8410 ~ 68 0
4 NGC 1614 AGN 04 34 00.027 -08 34 44.57   14.66 13.99     ~ 658 0

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