Related papers: The Diffuse Emission and a Variable ULX in the Ell…
We present evidence of the co-existence of either an AGN or an ultraluminous X-ray source (ULX), together with a young super stellar cluster in the 3 central parsecs of NGC4303. The galaxy contains a low luminosity AGN and hosts a number of…
We report the discovery of a new candidate ultraluminous X-ray source (ULX) in the nearby edge-on spiral galaxy NGC 891. The source, which has an absorbed flux of F_X ~ 10^-12 erg/s/cm^2 (corresponding to L_X > 10^40 erg/s at 9 Mpc), must…
We use archival Chandra X-ray Observatory data to investigate X-ray emission from early-type galaxies in the rich z=0.06 cluster Abell 3128. By combining the X-ray count-rates from an input list of optically-selected galaxies, we obtain a…
Images in the $H\alpha$ emission line are presented for 35 nearby objects observed with the 6-m BTA telescope. Three of them, NGC 3377, NGC 3384, and NGC 3390, are bright E and S0 galaxies, one is an edge-on Sd galaxy UGC 7321, two are…
A deep 75 ks {\it Chandra} ACIS--I data of NGC 2024 was analyzed, aiming at a search for diffuse X-ray emission in this one of the most nearby (415 pc) massive star-forming regions. After removing point sources, an extended emission was…
The vast majority of optically identified active galactic nuclei (AGNs) in the local Universe reside in host galaxies with prominent bulges, supporting the hypothesis that black hole formation and growth is fundamentally connected to the…
We report [O III] 5007 Angstrom and [N II] 6583 Angstrom emission from a globular cluster harboring the ultraluminous X-ray source (ULX) CXOJ033831.8-352604 in the Fornax elliptical galaxy NGC1399. No accompanying Balmer emission lines are…
We fit axisymmetric 3-integral dynamical models to NGC3379 using the line-of-sight velocity distribution obtained from HST/FOS spectra of the galaxy center and ground-based long-slit spectroscopy along four position angles, with the light…
We study the X-ray emission from NGC1277, a galaxy in the core of the Perseus cluster, for which van den Bosch et al. have recently claimed the presence of an UltraMassive Black Hole (UMBH) of mass 1.7 times 10^10 Msun, unless the IMF of…
Most ultraluminous X-ray sources (ULXs) display a typical set of properties not seen in Galactic stellar-mass black holes (BHs): higher luminosity Lx > 3 10^39 erg/s, unusually soft X-ray components (kT < 0.3 keV) and a characteristic…
(Abridged) We present results based on XMM-Newton observation of the nearby spiral galaxy M51 (NGC5194 and NGC5195). Two ULXs in NGC5194 show evidence for short-term variability, and all but two ULXs vary on long time scales (over a…
Early-type galaxies exhibit thermal and molecular resonance emission from dust that is shed and heated through stellar mass loss as a subset of the population moves through the AGB phase of evolution. Because this emission can give direct…
We present a Chandra X-ray observation of the X-ray bright E2 elliptical galaxy NGC4649. In addition to bright diffuse emission, we resolve 165 discrete sources, most of which are presumably low-mass X-ray binaries (LMXBs). As found in…
There are two proposed explanations for ultraluminous X-ray sources (ULXs) with luminosities in excess of $10^{39}$ erg s$^{-1}$. They could be intermediate-mass black holes (more than 100-1,000, solar masses, $M_\odot$) radiating at…
(Abridged) We report the results of a 20 ks Chandra ACIS-S observation of the interacting galaxy pair NGC 4485/4490. A total of 29 discrete X-ray sources are found coincident with NGC 4490, but only one is found within NGC 4485. The sources…
Winds from massive stars supply ~ 10^{-3} solar masss/year of gas to the central parsec of the Galactic Center. Spherically symmetric hydrodynamic calculations show that ~ 1 % of this gas, or ~ 10^{-5} solar masses/year, flows in towards…
We present BeppoSAX observations of 6 ``type-2'' LINER and ``transition'' galaxies (NGC3379, NGC3627, NGC4125, NGC4374, NGC5195 and NGC5879)from the Ho et al. (1997) spectroscopic sample of nearby galaxies. All objects are detected in the…
In the framework of understanding the gas and stellar kinematics and their relations to AGNs and galaxy evolution scenarios, we present spatially resolved distributions and kinematics of the stars and gas in the central $\sim 800$-pc radius…
We present the results of recent Chandra High-Energy Transmission Grating Spectrometer and Hubble Space Telescope Cosmic Origins Spectrograph observations of the nearby Seyfert 1 galaxy NGC 3783 which shows a strong, non-varying X-ray warm…
We present the results of the spatial and spectral analysis of the deep (~200 ksec) Chandra HETG observation of the changing look AGN NGC7582. During this observation NGC7582 was in a highly obscured state. Therefore, we considered also a…