O VI Emission Imaging of a Galaxy with the Hubble Space Telescope: a Warm Gas Halo Surrounding the Intense Starburst SDSS J115630.63+500822.1

Abstract

We report results from a new HST study of the OVI 1032,1038Å doublet in emission around intensely star-forming galaxies. The programme aims to characterize the energy balance in starburst galaxies and gas cooling in the difficult-to-map coronal temperature regime of 2-5 x $10^5$K. We present the first resolved image of gas emission in the OVI line. Our target, SDSS J1156+5008, is very compact in the continuum but displays OVI emission to radii of 23 kpc. The surface brightness profile is well fit by an exponential with a scale of 7.5kpc. This is ten times the size of the photoionized gas, and we estimate that 1/6 the total OVI luminosity comes from resonantly scattered continuum radiation. Spectroscopy - which closely resembles a stacked sample of archival spectra - confirms the OVI emission, and determines the column density and outflow velocity from blueshifted absorption. The combination of measurements enables several new calculations with few assumptions. The OVI regions fill only ~$10^{-3}$ of the volume. By comparing the cooling time with the cloud sound-crossing time, the cooling distance with the size, and the pressure in the OVI and nebular gas, we conclude that the OVI-bearing gas cannot have been lifted to the scale height at this temperature, and must be cooling in situ through this coronal temperature regime. The coronal phase contains ~1% of the ionized mass, and its kinetic energy is currently ~1% of the budget set by supernova feedback. However a much larger amount of the gas must have cooled through this phase during the star formation episode. The outflow exceeds the escape velocity and the gas may become unbound, but it will recombine before it escapes and become visible to Lyman (and OI) spectroscopy. The mapping of this gas represents a crucial step in further constraining galaxy formation scenarios and guiding the development of future satellites.

Accepted by the Astrophysical Journal. 25 pages, 11 figures. Section 7 presents calculated properties of warm halo gas. Version 2 fixes PDF compatibility issue for some PDF viewers

References in corpus (14)

• Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4
• The Effects of Stellar Rotation. II. A Comprehensive Set of Starburst99 Models
• The Search for the Missing Baryons at Low Redshift
• A High-Resolution Survey of Low-Redshift QSO Absorption Lines: Statistics and Physical Conditions of O VI Absorbers
• Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-Line Spectroscopy
• The Lyman alpha Reference Sample: Extended Lyman alpha Halos Produced at Low Dust Content
• The Lyman-alpha Reference Sample: I. Survey outline and first results for Markarian 259
• The Properties of Low Redshift Intergalactic O VI Absorbers Determined from High S/N Observations of 14 QSOs with the Cosmic Origins Spectrograph
• Empirical strong-line oxygen abundance calibrations from galaxies with electron temperature measurements
• Feedback in the local LBG Analog Haro 11 as probed by far-UV and X-ray observations
• Lyman alpha Emitting Galaxies in the Nearby Universe
• A STIS Survey for OVI Absorption Systems at 0.12 < z < 0.5 II.: Physical Conditions of the Ionised Gas
• Probing the IGM/Galaxy Connection Toward PKS0405-123 III: The Galaxy Survey and Correlations with OVI Absorbers
• Science drivers and requirements for an Advanced Technology Large Aperture Space Telescope (ATLAST): Implications for technology development and synergies with other future facilities

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