Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-05-13
Astrophys.Space Sci. 284 (2003) 507-510
Astronomy and Astrophysics
Astrophysics
10 pages, 11 figures, accepted for publication in A&A
Scientific paper
10.1023/A:1024012528834
The paper presents an analysis of the nearby QSO host I Zw 1 based on new J-band imaging data, obtained with ISAAC at the Very Large Telescope (VLT) of the European Southern Observatory (ESO). As one of the best-studied QSOs with exceptional properties lying between those of QSOs, narrow-line Seyfert 1s, and ultraluminous infrared galaxies, I Zw 1 is a prime candidate for a detailed case study of a QSO host. With its high angular resolution and sensitivity, the new J-band image provides strong evidence for an interaction between I Zw 1 and the western companion galaxy. We present a procedure for subtracting the QSO nucleus from the I Zw 1 image to obtain an undisturbed view on the underlying host galaxy. Based on the derived surface brightness profile and the gas rotation curve, the host is classified as a high-surface-brightness Freeman type I galaxy with a central disk surface brightness significantly larger than that of normal spirals. The surface-brightness profile is decomposed into a Plummer bulge and a Kuzmin disk with similar luminosities and a bulge-to-disk scale length ratio of 0.29, comparable to that of nearby spiral hosts with active galactic nuclei (AGN). Different models for the decomposition of the gas rotation curve are discussed. The resulting J-band mass-to-light ratio (M/L) of (0.7+/-0.4) M_sun/L_sun for the disk component suggests a mean solar-type stellar population with a tendency towards young stars. The bulge exhibits a lower M/L of 0.4+/-0.2 M_sun/L_sun, which supports previous findings of enhanced starburst activity in the nuclear and circumnuclear region.
Eckart Andreas
Moultaka Jihane
Pfalzner Susanne
Scharwaechter Julia
Staguhn Johannes G.
No associations
LandOfFree
I Zw 1: Decomposition of the Nearby QSO Host 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 I Zw 1: Decomposition of the Nearby QSO Host, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and I Zw 1: Decomposition of the Nearby QSO Host will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-91055