Optical Line Diagnostics of z~2 Optically Faint ULIRGs in the Spitzer Bootes Survey

Details Optical Line Diagnostics of z~2 Optically Faint ULIRGs in the Spitzer Bootes Survey Optical Line Diagnostics of z~2 Optically Faint ULIRGs in the Spitzer Bootes Survey

2007-02-28

arxiv.org/abs/astro-ph/0703003v1

Astrophys.J.663:204-217,2007

Astronomy and Astrophysics

Astrophysics

13 pages, ApJ accepted

Scientific paper

10.1086/518119

We present near-infrared spectroscopic observations for a sample of ten optically faint luminous infrared galaxies (R-[24]> 14) using Keck NIRSPEC and Gemini NIRI. The sample is selected from a 24 micron Spitzer MIPS imaging survey of the NDWFS Bootes field. We measure accurate redshifts in the range 1.31900 km/s) Halpha or Hbeta emission lines; the remaining three are type II AGN. Given their large mid-IR luminosities and faint optical magnitudes, we might expect these sources to be heavily extincted quasars, and therefore only visible as type II AGN. The visibility of broad lines in 70% of the sources suggests that it is unlikely that these AGN are being viewed through the mid-plane of a dusty torus. For four of the sources we constrain the Halpha/Hbeta Balmer decrement and estimate the extinction to the emission line region to be large for both type I and type II AGN, with A_Halpha > 2.4-5 mag. Since the narrow-line region is also extincted and the UV continuum emission from the host galaxies is extremely faint, this suggests that much of the obscuration is contributed by dust on large (~kpc) scales within the host galaxies. These sources may be examples of "host-obscured" AGN which could have space densities comparable or greater to that of optically luminous type I AGN with similar bolometric luminosities.

Affiliated with

Also associated with

No associations

Rating

Optical Line Diagnostics of z~2 Optically Faint ULIRGs in the Spitzer Bootes Survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Optical Line Diagnostics of z~2 Optically Faint ULIRGs in the Spitzer Bootes Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical Line Diagnostics of z~2 Optically Faint ULIRGs in the Spitzer Bootes Survey will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-119049