Related papers: The Diffuse Emission and a Variable ULX in the Ell…

We use deep Chandra observations to measure the emissivity of the unresolved X-ray emission in the elliptical galaxy NGC 3379. After elimination of bright, low-mass X-ray binaries with luminosities >10^{36 erg/sec, we find that the…

We present the properties of the discrete X-ray sources detected in our monitoring program of the `typical' elliptical galaxy, NGC 3379, observed with Chandra ACIS-S in five separate pointings, resulting in a co-added exposure of 324-ks.…

(Abridged) We observed the X-ray bright E3 galaxy NGC 1600 and nearby group members with the Chandra X-ray Observatory ACIS S3. Unresolved emission dominates the observation; however, we resolved some emission into 71 sources, most of which…

We report recent Chandra observations of the ULX in the elliptical galaxy NGC3379 that clearly detect two flux variability cycles. Comparing these data with the Chandra observation of ~5yr ago, we measure a flux modulation with a period of…

We have studied a highly variable ultraluminous X-ray source (ULX) in the Fornax galaxy NGC 1365, with a series of 12 Chandra and XMM-Newton observations between 2002 and 2006. In 2006 April, the source peaked at a luminosity ~ 3 x 10^{40}…

The relatively nearby (distance=24.1 Mpc) elliptical galaxy NGC821, hosting a central massive black hole but inactive at all wavelengths, was observed with Chandra for a total exposure of 230 ksec, to search for nuclear emission and gas…

NGC3379 is a well studied nearby elliptical for which optical investigations have claimed a little dark matter content, or even no dark matter. Recently, its total mass profile M(r) has been derived by exploiting Chandra observations of its…

We have spatially and spectrally resolved the sources of X-ray emission from the X-ray faint S0 galaxy NGC 1553 using an observation from the Chandra X-ray Observatory. The majority (70%) of the emission in the 0.3 - 10.0 keV band is…

We have measured the mass distribution in the central 35" = 1.7 kpc of the E5 galaxy NGC 3377. Stellar rotation velocity and velocity dispersion profiles (seeing sigma_* = 0.20 - 0.56 arcsec) and V-band surface photometry (sigma_* = 0.20 -…

Elliptical galaxy nuclei are the sites of the largest black holes known, but typically show little or no nuclear activity. We investigate this extreme quiescence using Chandra X-ray Observatory observations of the giant elliptical galaxies…

(Abridged) We used the Chandra X-ray Observatory ACIS S3 to image the X-ray faint elliptical galaxy NGC 4365 and lenticular galaxy NGC 4382. The observations resolve much of the X-ray emission into 99 and 58 sources, respectively, most of…

The intrinsic shape and orientation of the elliptical galaxy NGC 3379 are estimated by dynamical modeling. The maximal ignorance shape estimate, an average over the parameter space, is axisymmetric and oblate in the inner parts, with an…

The presence of hot X-ray emitting gas is ubiquitous in massive early-type galaxies. However, much less is known about the content and physical status of the hot X-ray gas in low-mass ellipticals. In the present paper we study the X-ray gas…

In 2016 we carried out a Swift monitoring program to track the X-ray hardness variability of eight type-I AGN over a year. The purpose of this monitoring was to find intense obscuration events in AGN, and thereby study them by triggering…

We report on the {\it Chandra} observations of the elliptical galaxy NGC 1399, concentrating on the X-ray sources identified with globular clusters (GCs). A large fraction of the 2-10 keV X-ray emission in the $8' \times 8'$ {\it Chandra}…

CO emission has been imaged at 2" resolution in the central 10 kpc of the barred spiral galaxy NGC 3367. This galaxy has bipolar synchrotron lobes out to a radii of 6 kpc, straddling the compact nucleus. The peak molecular emission is in a…

Recent observations with the Chandra X-ray Observatory have provided us with the capability to discriminate point sources, such as the supermassive black hole Sgr A*, from the diffuse emission within the inner 10'' of the Galaxy. The hot…

The analysis of a deep (579 ks) Chandra ACIS pointing of the elliptical galaxy NGC4278, which hosts a low luminosity AGN and compact radio emission, allowed us to detect extended emission from hot gas out to a radius of \sim 5 kpc, with a…

We suggest that the energy source of the observed diffuse gamma-ray emission from the direction of the Galactic center is the Galactic black hole Sgr A*, which becomes active when a star is captured at a rate of $\sim 10^{-5} $ yr^{-1}.…

We present results from a 30 ksec Chandra observation of the important starburst galaxy NGC 2782, covering the 0.3-10keV energy band. We find evidence of a superwind of small extent, that is likely in an early stage of development. We find…