Related papers: A new luminous supersoft X-ray source in NGC 300

XMMU J134736.6+173403 is an X-ray source discovered serendipitously by XMM-Newton which was found to be spatially coincident with a pair of galaxies, including a Seyfert 2 galaxy, but presented in 2003 a very sharp persistent flux drop of a…

We present a radio survey of X-ray sources in the Large and Small Magellanic clouds with the Australia Telescope Compact Array at 6.3 and 3.5 cm. Specifically, we have observed the fields of five LMC and two SMC supersoft X-ray sources, the…

We observed the globular cluster NGC 6652 with Chandra for 47.5 ks, detecting six known X-ray sources, as well as five previously undetected X-ray sources. Source A (XB 1832-330) is a well-known bright low-mass X-ray binary (LXMB). The…

V5116 Sgr (Nova Sgr 2005 No. 2), discovered on 2005 July 4, was observed with XMM-Newton in March 2007, 20 months after the optical outburst. The X-ray spectrum shows that the nova had evolved to a pure supersoft X-ray source, with no…

We present the results of the ongoing XMM-Newton survey of M31. 17 X-ray sources detected in the survey have bright radio counterparts, and 15 X-ray sources coincide with SNR candidates from optical and radio surveys. 15 out of 17 sources…

We report on possible associations between 6 globular clusters in the Virgo elliptical galaxy NGC 4472 (M49) and bright ($L_x > 10^{38}$ erg s$^{-1}$) very soft X-ray sources (VSSs). Two of the VSSs have broad-band spectral properties…

We report the discovery of a galaxy cluster serendipitously detected as an extended X-ray source in an offset observation of the group NGC 5044. The cluster redshift, z=0.281, determined from the optical spectrum of the brightest cluster…

Recent XMM-Newton and Chandra observations of the high mass X-ray binary LS 5039 / RX J1826.2-1450 caught the source in a faint X-ray state. In contrast with previous RXTE observations, we fail to detect any evidence of iron line emission.…

On 2003 September 17 INTEGRAL discovered a bright transient source 3 degrees from the Galactic Center, IGR J17544-2619. The field containing the transient was observed by XMM-Newton on 2003 March 17 and September 11 and 17. A bright source,…

We present the discovery of a luminous X-ray transient, serendipitously detected by Swift's X-ray Telescope (XRT) on 2020 February 5, located in the nucleus of the galaxy SDSS J143359.16+400636.0 at z=0.099 (luminosity distance $D_{\rm…

We report on the serendipitous discovery of a new transient in NGC 5907, at a peak luminosity of 6.4x10^{39} erg/s. The source was undetected in previous 2012 Chandra observations with a 3 sigma upper limit on the luminosity of 1.5x10^{38}…

After nearly a decade in quiescence, the accreting millisecond pulsar IGR J17511$-$3057 displayed a new outburst on 2025 February 11, its third since discovery, following previous activity in 2009 and 2015. We report on an XMM-Newton Target…

I analyze 101 observations from the ROSAT archive to search for X-ray sources in or near 55 globular clusters. New sources are found in the cores of NGC362 (a double source), NGC6121 (marginally significant), NGC6139, and NGC6266; and…

We present XMM-Newton, NuSTAR, Swift and Hubble Space Telescope observations of the Narrow-line Seyfert 1 galaxy Mrk 335 in a protracted low state in 2018 and 2019. The X-ray flux is at the lowest level so far observed, and the extremely…

The supernova impostor SN 2010da located in the nearby galaxy NGC 300, later identified as a likely supergiant B[e] high-mass X-ray binary, was simultaneously observed by NuSTAR and XMM-Newton between 2016 December 16 and 20, over a total…

We present a detailed analysis of XMM archival data of two Ultraluminous X-ray Sources (ULXs) in the nearby spiral galaxy NGC 1313: NGC 1313 X-1 and X-2. The spectral continuum of these sources was modeled with a soft thermal component plus…

[Abridged] Classical novae (CNe) represent the main class of supersoft X-ray sources (SSSs) in the central region of our neighbouring galaxy M 31. Only three confirmed novae and three SSSs have been discovered in globular clusters (GCs) of…

We report on the results of an EPIC XMM-Newton observation of the faint source SAXJ1748.2-2808 and the surrounding field. This source was discovered during the BeppoSAX Galactic center survey performed in 1997-1998. A spatial analysis…

In an XMM-Newton raster observation of the bright Local Group spiral galaxy M 33 we study the population of X-ray sources (X-ray binaries, supernova remnants) down to a 0.2--4.5 keV luminosity of 10^35 erg/s -- more than a factor of 10…

We present a sample of twenty-one ROSAT bright active galactic nuclei (AGN), representing a range of spectral classes, and selected for follow-up snap-shot observations with XMM-Newton. The typical exposure was between 5-10 ks. The objects…