skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: FIRST VIEWS OF A NEARBY LIRG: STAR FORMATION AND MOLECULAR GAS IN IRAS 04296+2923

Abstract

We present a first look at the local luminous infrared galaxy (LIRG) IRAS 04296+2923. This barred spiral galaxy, overlooked because of its location behind the Taurus molecular cloud, is among the half dozen closest (D = 29 Mpc) LIRGs. More IR-luminous than either M82 or the Antennae, it may be the best local example of a nuclear starburst caused by bar-mediated secular evolution. We present Palomar J and Pa {beta} images, Very Large Array continuum maps from {lambda}= 20-1.3 cm, a subarcsecond Keck Long Wavelength Spectrometer image at 11.7 {mu}m and Owens Valley Millimeter Array CO(1-0), {sup 13}CO(1-0), and 2.7 mm continuum images. The J-band image reveals a symmetric barred spiral galaxy. Two bright, compact mid-infrared and radio sources in the nucleus mark a starburst that is energetically equivalent to {approx}10{sup 5} O7 stars, separated by {approx}<50 pc. This is probably a pair of young super star clusters, with estimated stellar masses of {approx}10{sup 7} M{sub sun} each. The nuclear starburst is forming stars at the rate of {approx}12 {+-} 6 M{sub sun} yr{sup -1}, or about half of the total star formation rate for the galaxy of {approx}25 {+-} 10 M{sub sun} yr{sup -1}. IRAS 04296+2923 is very brightmore » in CO, and among the most gas-rich galaxies in the local universe. The {sup 12}CO luminosity of the inner half kpc is equivalent to that of the entire Milky Way. While the most intense CO emission is extended over a 15'' (2 kpc) diameter region, the nuclear starburst is confined to within 1''-2'' (150-250 pc) of the dynamical center. Based on masses obtained with {sup 13}CO, we find that the CO conversion factor in the nucleus is lower than the Galactic value, X {sup Gal}{sub CO} by a factor of three to four, typical of gas-rich spiral nuclei. The nuclear star formation efficiency (SFE) is {sup nuc}M{sub gas}/SFR{sup nuc} = 2.7 x 10{sup -8}yr{sup -1}, corresponding to a gas consumption timescale, {tau}{sup nuc}{sub SF} {approx} 4 x 10{sup 7} yr. The SFE is 10 times lower in the disk, with {tau}{sup disk}{sub SF} {approx} 3.3 x 10{sup 8} yr. The low absolute SFE in the disk implies that the molecular gas is not completely consumed before it drifts into the nucleus, and is capable of fueling a sustained nuclear starburst. IRAS 04296+2923 appears to be beginning a 100 Myr period as an LIRG, during which it will turn much of its 6 x 10{sup 9} M{sub sun} of molecular gas into a nuclear cluster of stars.« less

Authors:
 [1]; ;  [2];  [3];  [4]
  1. Department of Physics, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 (United States)
  2. Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1562 (United States)
  3. Department of Physics and Astronomy, Tel Aviv University, 69978 Ramat Aviv (Israel)
  4. Jet Propulsion Laboratory, 4800 Oak Grove Boulevard, MS 169-327, Pasadena, CA 91109 (United States)
Publication Date:
OSTI Identifier:
21443199
Resource Type:
Journal Article
Journal Name:
Astronomical Journal (New York, N.Y. Online)
Additional Journal Information:
Journal Volume: 140; Journal Issue: 5; Other Information: DOI: 10.1088/0004-6256/140/5/1294; Journal ID: ISSN 1538-3881
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANTENNAS; GALACTIC EVOLUTION; LUMINOSITY; MASS; MILKY WAY; SPECTROMETERS; STAR CLUSTERS; STAR EVOLUTION; STARS; UNIVERSE; ELECTRICAL EQUIPMENT; EQUIPMENT; EVOLUTION; GALAXIES; MEASURING INSTRUMENTS; OPTICAL PROPERTIES; PHYSICAL PROPERTIES

Citation Formats

Meier, David S, Turner, Jean L, Tsai, Chao-Wei, Beck, Sara C, Gorjian, Varoujan, and Van Dyk, Schuyler D., E-mail: dmeier@nmt.ed, E-mail: cwtsai@astro.ucla.ed, E-mail: sara@wise.tau.ac.i, E-mail: varoujan.gorjian@jpl.nasa.go, E-mail: vandyk@ipac.caltech.ed. FIRST VIEWS OF A NEARBY LIRG: STAR FORMATION AND MOLECULAR GAS IN IRAS 04296+2923. United States: N. p., 2010. Web. doi:10.1088/0004-6256/140/5/1294.
Meier, David S, Turner, Jean L, Tsai, Chao-Wei, Beck, Sara C, Gorjian, Varoujan, & Van Dyk, Schuyler D., E-mail: dmeier@nmt.ed, E-mail: cwtsai@astro.ucla.ed, E-mail: sara@wise.tau.ac.i, E-mail: varoujan.gorjian@jpl.nasa.go, E-mail: vandyk@ipac.caltech.ed. FIRST VIEWS OF A NEARBY LIRG: STAR FORMATION AND MOLECULAR GAS IN IRAS 04296+2923. United States. https://doi.org/10.1088/0004-6256/140/5/1294
Meier, David S, Turner, Jean L, Tsai, Chao-Wei, Beck, Sara C, Gorjian, Varoujan, and Van Dyk, Schuyler D., E-mail: dmeier@nmt.ed, E-mail: cwtsai@astro.ucla.ed, E-mail: sara@wise.tau.ac.i, E-mail: varoujan.gorjian@jpl.nasa.go, E-mail: vandyk@ipac.caltech.ed. 2010. "FIRST VIEWS OF A NEARBY LIRG: STAR FORMATION AND MOLECULAR GAS IN IRAS 04296+2923". United States. https://doi.org/10.1088/0004-6256/140/5/1294.
@article{osti_21443199,
title = {FIRST VIEWS OF A NEARBY LIRG: STAR FORMATION AND MOLECULAR GAS IN IRAS 04296+2923},
author = {Meier, David S and Turner, Jean L and Tsai, Chao-Wei and Beck, Sara C and Gorjian, Varoujan and Van Dyk, Schuyler D., E-mail: dmeier@nmt.ed, E-mail: cwtsai@astro.ucla.ed, E-mail: sara@wise.tau.ac.i, E-mail: varoujan.gorjian@jpl.nasa.go, E-mail: vandyk@ipac.caltech.ed},
abstractNote = {We present a first look at the local luminous infrared galaxy (LIRG) IRAS 04296+2923. This barred spiral galaxy, overlooked because of its location behind the Taurus molecular cloud, is among the half dozen closest (D = 29 Mpc) LIRGs. More IR-luminous than either M82 or the Antennae, it may be the best local example of a nuclear starburst caused by bar-mediated secular evolution. We present Palomar J and Pa {beta} images, Very Large Array continuum maps from {lambda}= 20-1.3 cm, a subarcsecond Keck Long Wavelength Spectrometer image at 11.7 {mu}m and Owens Valley Millimeter Array CO(1-0), {sup 13}CO(1-0), and 2.7 mm continuum images. The J-band image reveals a symmetric barred spiral galaxy. Two bright, compact mid-infrared and radio sources in the nucleus mark a starburst that is energetically equivalent to {approx}10{sup 5} O7 stars, separated by {approx}<50 pc. This is probably a pair of young super star clusters, with estimated stellar masses of {approx}10{sup 7} M{sub sun} each. The nuclear starburst is forming stars at the rate of {approx}12 {+-} 6 M{sub sun} yr{sup -1}, or about half of the total star formation rate for the galaxy of {approx}25 {+-} 10 M{sub sun} yr{sup -1}. IRAS 04296+2923 is very bright in CO, and among the most gas-rich galaxies in the local universe. The {sup 12}CO luminosity of the inner half kpc is equivalent to that of the entire Milky Way. While the most intense CO emission is extended over a 15'' (2 kpc) diameter region, the nuclear starburst is confined to within 1''-2'' (150-250 pc) of the dynamical center. Based on masses obtained with {sup 13}CO, we find that the CO conversion factor in the nucleus is lower than the Galactic value, X {sup Gal}{sub CO} by a factor of three to four, typical of gas-rich spiral nuclei. The nuclear star formation efficiency (SFE) is {sup nuc}M{sub gas}/SFR{sup nuc} = 2.7 x 10{sup -8}yr{sup -1}, corresponding to a gas consumption timescale, {tau}{sup nuc}{sub SF} {approx} 4 x 10{sup 7} yr. The SFE is 10 times lower in the disk, with {tau}{sup disk}{sub SF} {approx} 3.3 x 10{sup 8} yr. The low absolute SFE in the disk implies that the molecular gas is not completely consumed before it drifts into the nucleus, and is capable of fueling a sustained nuclear starburst. IRAS 04296+2923 appears to be beginning a 100 Myr period as an LIRG, during which it will turn much of its 6 x 10{sup 9} M{sub sun} of molecular gas into a nuclear cluster of stars.},
doi = {10.1088/0004-6256/140/5/1294},
url = {https://www.osti.gov/biblio/21443199}, journal = {Astronomical Journal (New York, N.Y. Online)},
issn = {1538-3881},
number = 5,
volume = 140,
place = {United States},
year = {Mon Nov 15 00:00:00 EST 2010},
month = {Mon Nov 15 00:00:00 EST 2010}
}