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Glenn White

Publications and source records attributed to Glenn White.

20 records · Page 2Linked to original sources

Ultraluminous and Hyperluminous Infrared Galaxies in the SDSS, 2dFGRS and 6dFGS

We present a result of cross-correlating the Infrared Astronomical Satellite Faint Source Catalogue (IRAS FSC) with the spectroscopic catalogues of galaxies in the Fourth Data Release of Sloan Digital Sky Survey (SDSS), the Final Data Release of 2dF Galaxy Redshift Survey (2dFGRS) and the Second Data Release of 6dF Galaxy Survey (6dFGS). We have identified 324 ultraluminous infrared galaxies (ULIRGs) including 190 newly discovered ULIRGs, and 2 hyperluminous infrared galaxies (HLIRGs). Adding these new ULIRGs, we increase the number of known ULIRGs by about 30 per cent. The reliability of the cross-correlation is estimated using the likelihood ratio method. The incompleteness of our sample introduced by the identification procedure in this study is estimated to be about 5 per cent. Our sample covers the redshift range of z=0.037$-$0.517 with a median redshift of $\bar{z}$=0.223, which is larger than that ($\bar{z}$=0.184) of the sample of previously known ULIRGs.

astro-ph↗

Detection of the 62 micron Crystalline Water Ice Feature in Emission toward HH7 with ISO-LWS

We report the detection of the 62 micron feature of crystalline water ice in emission towards the bow-shaped Herbig-Haro object HH 7. Significant amounts of far infrared continuum emission are also detected between 10 and 200 micron, so that Herbig-Haro objects cease to be pure emission-line objects at FIR wavelengths. The formation of crystalline water ice mantles requires grain temperatures T > 100 K at the time of mantle formation, suggesting that we are seeing material processed by the HH 7 shock front. The deduced ice mass is \~2e-5 solar masses corresponding to a water column density N~ 1e18 cm-3; an estimate of the [H2O]/[H] abundance yields values close to the interstellar gas-phase oxygen abundance. The relatively high dust temperature and the copious amounts of gas-phase water needed to produce the observed quantity of crystalline water ice, suggest a scenario where both dissociative and non-dissociative shocks co-exist. The timescale for ice mantle formation is of the order of ~400 years, so that the importance of gas-phase water cooling as a shock diagnostic may be greatly diminished.

astro-ph↗