Related papers: Chandra's insights into SN 2023ixf

We estimate the progenitor and explosion properties of the nearby Type II SN 2023ixf using a synthetic model grid of Type II supernova light curves. By comparing the light curves of SN 2023ixf with the pre-existing grid of Type II…

We present a detailed analysis of the intrinsic X-ray absorption in the Seyfert 1 galaxy NGC 4151 using Chandra/HETGS data obtained 2002 May, as part of a program which included simultaneous UV spectra using HST/STIS and FUSE. NGC 4151 was…

We report the discovery of eight X-ray sources with periodic variability in 487 ks of observations of the Galactic center with Chandra. The sources are identified from a sample of 285 objects detected with 100-4200 net counts. Their periods…

We report on the present stage of SN 1987A as observed by the Chandra X-ray Observatory. We reanalyze published Chandra observations and add three more epochs of Chandra data to get a consistent picture of the evolution of the X-ray fluxes…

We report on a second epoch of Chandra X-ray imaging spectroscopy of the spatially-resolved old nova remnant GK Persei. An ACIS-S3 observation of 97.4 ks was conducted in November 2013 after a lapse of 13.8 years from the last visit in…

BeppoSAX observed NGC4258 on December 1998, when its 2-10 keV luminosity was \~1E41 erg/s. 100% variability is observed in the 3-10 keV band on timescales of a half a day while 20% variability is observed on timescales of one hour. The…

LkHA312 has been observed serendipitously with the ACIS-I detector on board Chandra with 26h continuous exposure. This H_alpha emission line star belongs to the star-forming region M78 (NGC2068). From the optical and NIR data, we show that…

We report the results of a 2-month campaign conducted with the Chandra X-ray observatory to monitor the ultraluminous X-ray source (ULX) NGC 5204 X-1. This was composed of a 50-ks observation, followed by ten 5-ks follow-ups spaced…

We report on our study of supernova (SN) 2022xxf based on observations obtained during the first four months of its evolution. The light curves (LCs) display two humps of similar maximum brightness separated by 75 days, unprecedented for a…

We present X-ray spectra of the nucleus of the nearby radio galaxy Centaurus A from observations with the XMM-Newton EPIC CCD cameras (two exposures separated by 12 months) and the Chandra HETGS. For the first time in an FRI type galaxy, we…

$\sim$18 yr after the supernova explosion, the blast wave of SNR 1987A is entering the main body of the equatorial circumstellar material, which is causing a dramatic brightening of the remnant. We recently reported the observational…

We present BeppoSAX observations of the Seyfert 1.8 galaxy NGC1365 in the 0.1--100 keV range. The source was 6 times brighter than during an ASCA observation 3 years earlier. The 4--10 keV flux is highly variable during the BeppoSAX…

The quasi-persistent neutron star low-mass X-ray binary MXB 1659-29 went into quiescence in 2001, and we have followed its quiescent X-ray evolution since. Observations over the first 4 years showed a rapid drop in flux and temperature of…

Early observations of transient explosions can provide vital clues to their progenitor origins. In this paper we present the nearby Type Iax (02cx-like) supernova (SN), SN 2020udy that was discovered within hours ($\sim$7 hr) of estimated…

We present Chandra and XMM-Newton X-ray data of NGC5253, a local starbursting dwarf elliptical galaxy, in the early stages of a starburst episode. Contributions to the X-ray emission come from discrete point sources and extended diffuse…

Supernovae that interact with hydrogen-poor, helium-rich circumstellar material (CSM), known as Type Ibn supernovae (SNe Ibn), present a unique opportunity to probe mass-loss processes in massive stars. In this work, we report the first…

We report the results of the {\it Chandra} ACIS-S observations of the elliptical galaxy NGC 821, which harbors a supermassive nuclear black hole (of $3.5 \times 10^7 M_{\odot}$), but does not show sign of AGN activity. A small,…

We report the results from a Chandra TOO observation of the low-luminosity Narrow Line Seyfert 1 galaxy NGC 4051, obtained during a 6-week duration low-flux state in 2001 February. During the Chandra observation, the 2-10 keV source flux…

We present an analysis of Chandra observations of two high-redshift clusters of galaxies, ClJ1113.1-2615 at z=0.725 and ClJ0152.7-1357 at z=0.833. We find ClJ1113 to be relaxed with kT=4.3^{+0.5}_{-0.4}keV and a mass (within the virial…

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…