Related papers: No Evidence for [O III] Variability in Mrk 142
The narrow-line Seyfert 1 galaxy (NLS1) Mrk 335 has been continuously monitored with Swift since May 2007 when it fell into a long-lasting, X-ray low-flux interval. Results from the nearly 11 years of monitoring are presented here.…
We present results of temporal and spectral analyses on four XMM-Newton EPIC pn observations of IRAS 17020+4544, a narrow-line Seyfert 1 galaxy with evidence of a radio jet. Analysis of the light curves reveals that this radio-loud source…
[Abridged]The strong asymmetry in the optical [O III]$\lambda$5007 emission line is one of the best signatures of AGN-driven warm (~10$^4$ K) ionized gas outflows on host galaxy scales. While large spectroscopic surveys like SDSS have…
We report on the X-ray time resolved spectral analysis of XMM-Newton observations of NGC 3783. The main goal is to detect transient features in the Fe K line complex, in order to study the dynamics of the innermost accretion flow. We…
We study X-ray and UV emission from the narrow-line Seyfert 1 galaxy II~Zw~177 using a $137\ks$ long and another $13\ks$ short \xmm{} observation performed in 2012 and 2001, respectively. Both observations show soft X-ray excess emission…
We study short-timescale 340 GHz flux-density variability of Sgr A* using ALMA Cycle 3 observations. Careful self-calibration enabled 10 s snapshot imaging with very high effective image-domain SNR, allowing high-cadence monitoring of…
The X-ray variability of the narrow line Seyfert 1 galaxy Markarian 766 is studied using 9 ROSAT PSPC datasets. The spectrum is well described by a power law combined with a blackbody (kT~ 70 eV) soft excess. Examination of flux ratio…
We report the results of a detailed analysis of a deep simultaneous $130\,\rm ks$ \textit{XMM-Newton & NuSTAR} observation of the nearby ($z=0.0315$) and bright ($L_{\rm bol}\sim3\times10^{45}\,\rm erg\,s^{-1}$) starburst-AGN Seyfert\,2…
(Abridged) Spiral galaxies often have extended outflows that permeate beyond the region of the disk. Such outflows have been seen both in starburst galaxies, actively star forming galaxies and galaxies with an AGN. In the latter galaxies it…
We report the detection of optical and X-ray variability in the least luminous known Seyfert galaxy, NGC4395. The featureless continuum changed by a factor of 2 in 6 months, which is typical of more luminous AGN. The largest variation was…
We present a series of RXTE observations of the nearby obscured Seyfert galaxies ESO103-G35, IC5063, NGC4507 and NGC7172. The period of monitoring ranges from seven days for NGC7172 up to about seven months for ESO103-G035. The spectra of…
In the early stages of star formation, a protostar is deeply embedded in an optically thick envelope such that it is not directly observable. Variations in the protostellar accretion rate, however, will cause luminosity changes that are…
We present a multi-wavelength study of the radio-loud narrow line Seyfert 1 galaxy (NLSy1), 1H 0323+342, detected by Fermi Gamma Ray Space Telescope. Multi-band light curves show many orphan X-ray and optical flares having no corresponding…
We performed a detailed spectral and timing analysis of a Seyfert 1 galaxy Mrk 509 using data from the Neil Gehrels Swift observatory that spanned over ~13 years between 2006 and 2019. To study the variability properties from the optical/UV…
We report on the deepest X-ray observation of the narrow-line Seyfert 1 galaxy Mrk 335 in the low-flux state obtained with Suzaku. The data are compared to a 2006 high-flux Suzaku observation when the source was ~10-times brighter.…
We present an XMM-Newton observation of the bright, narrow-line, ultrasoft Seyfert 1 galaxy Ton S180. The 0.3-10 keV X-ray spectrum is steep and curved, showing a steep slope above 2.5 keV (Gamma ~ 2.3) and a smooth, featureless excess of…
Context. Obscuration events caused by outflowing clumps or streams of high column density, low ionisation gas, heavily absorbing the X-ray continuum, have been witnessed in a number of Seyfert galaxies. Aims. We report on the X-ray…
We present {\it ASCA} observations of the Seyfert 1 galaxies Mrk~1040 and MS~0225.5+3121. Mrk~1040 was found to have decreased in flux by almost a factor of 4 since an {\it EXOSAT} observation 10\,years ago. The energy spectrum of Mrk~1040…
We report on our Spitzer observations of the anomalous X-ray pulsar 4U 0142+61, made following a large X-ray burst that occurred on 2007 February 7. To search for mid-infrared flux variations, four imaging observations were carried out at…
We present the first multi-parameter analysis of the narrow line AGN clustering properties. Estimates of the two-point correlation function (CF) based on SDSS DR2 data reveal that Seyferts are clearly less clustered than normal galaxies,…