The Hidden H I-Massive Luminous Infrared Galaxy HIZOA J0836-43: Inside-Out Galaxy Formation

October 2008 • 2008ApJ...686L..17C

Authors • Cluver, M. E. • Jarrett, T. H. • Appleton, P. N. • Kraan-Korteweg, R. C. • Woudt, P. A. • Koribalski, B. S. • Donley, J. L. • Wakamatsu, K. • Nagayama, T.

Abstract • HIZOA J0836-43 is an extreme gas-rich (M_{H I} = 7.5 × 10¹⁰ M_⊙) disk galaxy which lies hidden behind the strongly obscuring Vela region of the Milky Way. Utilizing observations from the Spitzer Space Telescope, we have found it to be a luminous infrared starburst galaxy with a star formation rate of ~ 21 M_⊙ yr^-1, arising from exceptionally strong molecular PAH emission (L_{7.7μ m} = 1.50 × 10⁹ L_⊙) and far-infrared emission from cold dust. The galaxy exhibits a weak mid-infrared continuum compared to other star-forming galaxies and U/LIRGs. This relative lack of emission from small grains suggests atypical interstellar medium conditions compared to other starbursts. We do not detect significant [Ne V] or [O IV], which implies an absent or very weak AGN. The galaxy possesses a prominent bulge of evolved stars and a stellar mass of 4.4(±1.4) × 10¹⁰ M_⊙. With its plentiful gas supply and current star formation rate, a doubling of stellar mass would occur on a timescale of ~2 Gyr. Compared to local galaxies, HIZOA J0836-43 appears to be a "scaled up" spiral undergoing inside-out formation, possibly resembling stellar disk building processes at intermediate redshifts.

This work is based on observations made with the Spitzer Space Telescope, which is operated by JPL/Caltech under a contract with NASA.

Links

• PREPRINT http://arxiv.org/abs/0808.4040
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2008ApJ...686L..17C
• ELECTR https://iopscience.iop.org/article/10.1086/592784
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2008ApJ...686L..17C
• PDF https://iopscience.iop.org/article/10.1086/592784/pdf
• DATA https://irsa.ipac.caltech.edu/bibdata/2008/C/2008ApJ...686L..17C.html