相关论文: Starbursts in active galaxy nuclei: observational …
Active galaxies are often associated with starbursts, which are possible sources of fuelling for the nuclear black holes. By means of optical (3500-7500 A) spectroscopic and narrow-band photometric data (H_alpha+[NII]6548,6583 and…
We assess the potential of nuclear starburst disks to obscure the Seyfert-like AGN that dominate the hard X-ray background at z~1. Over 1200 starburst disk models, based on the theory developed by Thompson et al., are calculated for five…
We analyse star formation in the nuclei of 9 Seyfert galaxies at spatial resolutions down to 0.085arcsec, corresponding to length scales of less than 10pc in some objects. Our data were taken mostly with the near infrared adaptive optics…
We present near-infrared spectra for a sample of galaxies with ambiguous optical emission line ratios. These galaxies fall between starbursts and Seyferts in the usual optical diagnostic diagrams. We find a similar result with the…
We present near-infrared K- (1.9-2.5 micrometer) and L- (2.8-4.2 micrometer) band spectroscopy of 22 Seyfert nuclei. We use two methods to investigate the presence of nuclear starbursts: (1) the Polycyclic Aromatic Hydrocarbon (PAH)…
We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…
We examine the possibility of the active galactic nucleus (AGN) obscuration by dusty gas clouds that spurt out from circumnuclear starburst regions. For the purpose, the dynamical evolution of gas clouds is pursued, including the effects of…
We investigated the correlation between nuclear/circumnuclear starbursts around the active galactic nuclei (AGNs) and the AGN activities for 43 Seyfert galaxies in the CfA and 12 micron samples. We found that circumnuclear starburst…
The mid infrared spectra of the starbursts show the 9.7$\mu m$ silicate absorption feature and strong mid infrared emission bands centered at 6.2, 7.7, and 11.3 $\mu$m. Illustrative models of the {\it active} galaxies are presented: As the…
We analyze X-ray spectra and images of a sample of Seyfert 2 galaxies that unambiguously contain starbursts, based on their optical and UV characteristics. Although all sample members contain active galactic nuclei (AGNs), supermassive…
We present the results of X-ray imaging and spectroscopic analysis of a sample of Seyfert 2 galaxies that contain starbursts, based on their optical and UV characteristics. These composite galaxies exhibit extended, soft, thermal X-ray…
Previous studies of the Na I D interstellar absorption line doublet have shown that galactic winds occur in most galaxies with high infrared luminosities. However, in infrared-bright composite systems where a starburst coexists with an…
Galactic superwinds occur in almost all infrared-luminous galaxies with star formation rates (SFRs) above 10 M_sun/yr, as shown by studies of the NaI D interstellar absorption line. We demonstrate that this result also applies to…
We examine a representative sample of 35 Seyfert 2 nuclei. Previous work has shown that nearly 1/2 of these nuclei show the direct (but difficult-to-detect) spectroscopic signatures at optical-UV wavelengths of the hot massive stars that…
We present observational evidences that dust in the circumnuclear region of AGNs has different properties than in the Galactic diffuse interstellar medium. By comparing the reddening of optical and infrared broad lines and the X-ray…
It was once common to regard Seyfert and starburst galaxies as completely different types of object, but there is growing recognition that these classifications refer to the extremes of a continuous spectrum of galaxy types. In a previous…
We present near and mid--IR observations of a sample of Seyfert II galaxies drawn from the $12\mu$m Galaxy Sample. The sample was observed in the J, H, K, L, M and N bands. Galaxy Surface Brightness Profiles are modeled using nuclear,…
We investigate 'activity' and 'quiescence' in galaxies at relatively high redshifts by modelling the line(and continuum) spectra of each object. The models account consistently for photoionization and shocks. We claim that the starburst…
We present a 5-8 micron analysis of the Spitzer-IRS spectra of 71 ultraluminous infrared galaxies (ULIRGs) with redshift z < 0.15, devoted to the study of the role of active galactic nuclei (AGN) and starbursts (SB) as the power source of…
We report on infrared K- (2-2.5 micron) and L-band (2.8-4.1 micron) slit spectroscopy of 23 Seyfert 1 galaxies in the CfA and 12 micron samples. A polycyclic aromatic hydrocarbon (PAH) emission feature at 3.3 micron in the L band is…