Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-10-07
Astrophysical Journal 706 (2009) 508-515
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Accepted for publication in ApJ
Scientific paper
We model the optical to far-infrared SEDs of a sample of six type-1 and six type-2 quasars selected in the mid-infrared. The objects in our sample are matched in mid-IR luminosity and selected based on their Spitzer IRAC colors. We obtained new targeted Spitzer IRS and MIPS observations and used archival photometry to examine the optical to far-IR SEDs. We investigate whether the observed differences between samples are consistent with orientation-based unification schemes. The type-1 objects show significant emission at 3 micron. They do not show strong PAH emission and have less far-IR emission on average when compared to the type-2 objects. The SEDs of the type-2 objects show a wide assortment of silicate features, ranging from weak emission to deep silicate absorption. Some also show strong PAH features. In comparison, silicate is only seen in emission in the type-1 objects. This is consistent with some of the type-2s being reddened by a foreground screen of cooler dust, perhaps in the host galaxy itself. We investigate the AGN contribution to the far-IR emission and find it to be significant. We also estimate the star formation rate for each of the objects by integrating the modeled far-IR flux and compare this with the SFR found from PAH emission. We find the type-2 quasars have a higher average SFR than the type-1 quasars based on both methods, though this could be due to differences in bolometric luminosities of the objects. While we find pronounced differences between the two types of objects, none of them are inconsistent with orientation-based unification schemes.
Armus Lee
Canalizo Gabriela
Hiner Kyle D.
Lacy Mark
Ridgway Susan
No associations
LandOfFree
An Infrared Comparison of Type-1 and Type-2 Quasars 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 An Infrared Comparison of Type-1 and Type-2 Quasars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An Infrared Comparison of Type-1 and Type-2 Quasars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-351777