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G515, Revisited. I. Stellar Populations And Evidence Of Nuclear Activity In A Luminous "E+A" Galaxy

Charles T. Liu·Eric J. Hooper·Karen O'Neil·David Thompson·Marsha Wolf·Thorsten Lisker
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Abstract

We present multiwavelength observations of the very luminous "E+A" galaxy known as G515 (J152426.55+080906.7), including deep K_s imaging, spatially resolved H-alpha spectroscopy, and radio observations. The data, together with detailed spectral synthesis of the galaxy's integrated stellar population, show that G515 is a ~1 Gyr old post-merger, post-starburst galaxy. We detect no Balmer line emission in the galaxy, although there is a small amount of [NII]6548,6583A emission. The galaxy's H I mass has a 2-sigma upper limit of 1.0 * 10^9 solar masses. IRAS detections in the 60-micron and 100-micron bands indicate a far infrared luminosity of ~5.8 * 10^10 solar luminosities. A small amount (~3 mJy) of radio continuum flux, which appears to be variable, has been detected. The data suggest that G515 may have once been an ultraluminous infrared galaxy, and may harbor a weak, dust-obscured active nucleus.

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Charles T. Liu, Eric J. Hooper, Karen O'Neil, David Thompson, Marsha Wolf, Thorsten Lisker. 2006-12-02. G515, Revisited. I. Stellar Populations And Evidence Of Nuclear Activity In A Luminous "E+A" Galaxy. https://doi.org/10.1086/511328

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