We present an analysis of the active galaxy SDSS J131642.90+175332.5, which is remarkable because all of its narrow emission lines are double-peaked, and because it additionally shows an extra broad...
Komossa, S., Zhou, H., Rau, A., Dopita, M., Gal-Yam, A., Greiner, J., ...
The galaxy SDSSJ095209.56+214313.3 (SDSSJ0952+2143 hereafter) showed remarkable emission-line and continuum properties and strong emission-line variability first reported in 2008 (Paper I). The...
Multiwavelength View of the Inner Spiral of NGC 1365 (2009)
We study the extended nuclear emission of the starburst galaxy NGC 1365. A weak obscured AGN and a strong starburst both contribute to the observed X-ray, optical, infrared, and radio emission in the...
Komossa, S., Zhou, H., Rau, A., Dopita, M., Gal-Yam, A., Greiner, J., ...
The galaxy SDSSJ0952+2143 showed remarkable emission-line properties first reported in 2008 (paper I), which are the consequence of a powerful high-energy flare. Here we report follow-up observations...
A candidate tidal disruption event in the Galaxy cluster Abell 3571 (2009)
Cappelluti, N., Ajello, M., Rebusco, P., Komossa, S., Bongiorno, A., Clemens, C., ...
Context. Tidal disruption events are possible sources of temporary nuclear activity in galactic nuclei and can be considered as good indicators of the existence of supermassive black holes in the...
Black Hole Masses of Intermediate-Redshift Quasars: Near Infrared Spectroscopy (2009)
Dietrich, Matthias, Mathur, Smita, Grupe, Dirk, Komossa, S.
We present near-infrared spectra of ten luminous, intermediate redshift quasars observed with SofI at the NTT of ESO/La Silla. With these rest-frame optical spectra we probe the Hb -[OIII] emission...
A candidate tidal disruption event in the Galaxy cluster Abell 3571 (2009)
Cappelluti, N., Ajello, M., Rebusco, P., Komossa, S., Bongiorno, A., Clemens, C., ...
Tidal disruption events are possible sources of temporary nuclear activity in galactic nuclei and can be considered as good indicators of the existence of super massive black holes in the centers of...
A candidate tidal disruption event in the galaxy cluster Abell 3571 (2009)
Cappelluti, N., Ajello, M., Rebusco, P., Komossa, S., Bongiorno, A., Clemens, C., ...
Komossa, S., Zhou, H., Rau, A., Dopita, M., Gal-Yam, A., Greiner, J., ...
The research focuses on the transformation of the urban block in relation to the public realm of the two great Dutch cities Amsterdam and Rotterdam throughout the last 400 years. In order to analyse...
We consider the consequences of gravitational wave recoil for unified models of active galactic nuclei (AGNs). Spatial oscillations of supermassive black holes (SMBHs) around the cores of galaxies...
Evolution of tidal disruption candidates discovered by XMM-Newton (2008)
Esquej, P., Saxton, R. D., Komossa, S., Read, A. M., Freyberg, M. J., Hasinger, G., ...
It has been demonstrated that active galactic nuclei are powered by gas accretion onto supermassive black holes located at their centres. The paradigm that the nuclei of inactive galaxies are also...
A Population of Radio-loud Narrow Line Seyfert 1 Galaxies with Blazar-like Properties? (2008)
Yuan, W., Zhou, H. Y., Komossa, S., Dong, X. B., Wang, T. G., Lu, H. L., ...
(abridged) We present a comprehensive study of a sample of 23 genuine radio-loud NLS1 galaxies which have the radio-loudness parameters greater than 100. The radio sources of the sample are...
Komossa, S., Zhou, H., Wang, T., Ajello, M., Ge, J., Greiner, J., ...
We report the discovery of superstrong, fading, high-ionization iron line emission in the galaxy SDSS J095209.56+214313.3 (SDSS J0952+2143 hereafter), which must have been caused by an X-ray outburst...
A recoiling supermassive black hole in the quasar SDSSJ092712.65+294344.0? (2008)
We present SDSSJ092712.65+294344.0 as the best candidate to date for a recoiling supermassive black hole (SMBH). SDSSJ0927+2943 shows an exceptional optical emission-line spectrum with two sets of...
Komossa, S., Zhou, H., Wang, T., Ajello, M., Ge, J., Greiner, J., ...
We report the discovery of superstrong, fading, high-ionization iron line emission in the galaxy SDSSJ095209.56+214313.3 (SDSSJ0952+2143 hereafter), which must have been caused by an X-ray outburst...
Chandra LETGS spectroscopy of the Quasar MR2251-178 and its warm absorber (2008)
Ramírez, J. M., Komossa, S., Burwitz, V., Mathur, S.
We present an analysis of our Chandra Low Energy Transmission Grating Spectrometer (LETGS) observation of the quasar MR2251-178. The warm absorber of MR2251-178 is well described by a hydrogen column...
On the nature of Seyfert galaxies with high [OIII]5007 blueshifts (2008)
Komossa, S., Xu, D., Zhou, H., Storchi-Bergmann, T., Binette, L.
We have studied the properties of Seyfert galaxies with high [OIII]5007 blueshifts (`blue outliers'), originally identified because of their strong deviation from the M_BH - sigma relation of normal,...
Komossa, S., Zhou, H., Wang, T., Ajello, M., Ge, J., Greiner, J., ...
On the nature of Seyfert galaxies with high [O III] λ5007 blueshifts (2008)
Komossa, S., Xu, D., Zhou, H., Storchi-Bergmann, T., Binette, L.
Evolution of tidal disruption candidates discovered by XMM-Newton (2008)
Esquej, P., Saxton, R. D., Komossa, S., Read, A. M., Freyberg, M. J., Hasinger, G., ...
A population of radio-loud narrow-line Seyfert 1 galaxies with blazar-like properties? (2008)
Yuan, W., Zhou, H. Y., Komossa, S., Dong, X. B., Wang, T. G., Lu, H. L., ...
Narrow-line Seyfert 1 Galaxies (2008)
I provide a short review of the properties of Narrow-line Seyfert 1 (NLS1) galaxies across the electromagnetic spectrum and of the models to explain them. Their continuum and emission-line properties...
Narrow-Line Seyfert 1 Galaxies (2007)
I provide a short review of the properties of Narrow-line Seyfert 1 (NLS1) galaxies across the electromagnetic spectrum and of the models to explain them. Their continuum and emission-line properties...
Narrow-line Seyfert 1 Galaxies and the M_BH - sigma Relation (2007)
We have studied the location of narrow-line Seyfert 1 (NLS1) galaxies and broad-line Seyfert 1 (BLS1) galaxies on the M_BH - sigma relation of non-active galaxies. We find that NLS1 galaxies as a...
The spectral energy distributions of AGN with double-peaked Balmer lines (2007)
Strateva, I., Brandt, W. N., Eracleous, M., Garmire, G., Komossa, S.
The Spectral Energy Distributions of AGN with Double-Peaked Balmer Lines (2006)
Strateva, I., Brandt, W. N., Eracleous, M., Garmire, G., Komossa, S.
We summarize the optical, UV, and X-ray properties of double-peaked emitters -- AGN with double-peaked Balmer emission lines believed to originate in the AGN accretion disk. We focus on the X-ray...
Bennert, N, Jungwiert, B, Komossa, S, Haas, M, Chini, R
While [OIII] narrow-band imaging is commonly used to measure the size of the narrow-line regions (NLRs) in active galactic nuclei (AGNs), it can be contaminated by emission from surrounding...
Radio-loud Narrow-Line Type 1 Quasars (2006)
Komossa, S., Voges, W., Xu, D., Mathur, S., Lemson, G., ...
We present the first systematic study of (non-radio-selected) radio-loud narrow-line Seyfert 1 (NLS1) galaxies. Cross-correlation of the `Catalogue of Quasars and Active Nuclei' with several radio...
Size and properties of the NLR in the Seyfert-2 galaxy NGC 1386 (2006)
Bennert, N., Jungwiert, B., Komossa, S., Haas, M., Chini, R.
The radio loud narrow-line quasar SDSSJ172206.03+565451.6 (2005)
Komossa, S., Voges, W., Xu, D., Mathur, S., Anderson, S. F.
We report identification of the radio loud narrow-line quasar SDSS J172206.03+565451.6 which we found in the course of a search for radio loud narrow-line Active Galactic Nuclei (AGN)....
Multifrequency Observations of the Gamma-Ray Blazar 3C 279 in Low-State during Integral AO-1 (2004)
Collmar, W., Böttcher, M., Burwitz, V., Courvoisier, T., Komossa, S., Kretschmar, P., ...
We report first results of a multifrequency campaign from radio to hard X-ray energies of the prominent gamma-ray blazar 3C 279 during the first year of the INTEGRAL mission. The variable blazar was...
Follow-Up Chandra Observations of Three Candidate Tidal Disruption Events (2004)
Halpern, J. P., Gezari, S., Komossa, S.
Large-amplitude, high-luminosity soft X-ray flares were detected by the ROSAT All-Sky Survey in several galaxies with no evidence of Seyfert activity in their ground-based optical spectra. These...
Komossa, S., Halpern, J., Schartel, N., Hasinger, G., Santos-Lleo, M., Predehl, P.
It has been suggested that an unavoidable consequence of the existence of supermassive black holes, and the best diagnostic of their presence in non-active galaxies, would be occasional tidal...
Mkn 1239: A highly polarized NLS1 with a steep X-ray spectrum and strong NeIX emission (2004)
Grupe, D., Mathur, S., Komossa, S.
We report the results of an XMM-Newton observation of the Narrow-Line Seyfert 1 galaxy Mkn 1239. This optically highly polarized AGN has one of the steepest X-ray spectra found in AGN with alpha-X =...
Multifrequency observations of the gamma-ray blazar 3C 279 in low-state during INTEGRAL AO-1 (2004)
Collmar, W., Böttcher, M., Burwitz, V., Courvoisier, T., Komossa, S., Kretschmar, P., ...
Follow-up STIS spectroscopy of three candidate tidal disruption events (2004)
Gezari, S., Halpern, J., Komossa, S., Grupe, D., Leighly, K.
Follow-Up HST/STIS Spectroscopy of Three Candidate Tidal Disruption Events (2003)
Gezari, S., Halpern, J. P., Komossa, S., Grupe, D., Leighly, K. M.
Large amplitude, high luminosity soft X-ray flares were detected by the ROSAT All-Sky Survey in several galaxies with no evidence for Seyfert activity in their ground-based optical spectra. These...
Komossa, S., Burwitz, V., Hasinger, G., Predehl, P., Kaastra, J. S., Ikebe, Y.
Ultraluminous infrared galaxies (ULIRGs) are outstanding due to their huge luminosity output in the infrared, which is predominantly powered by superstarbursts and/or hidden active galactic nuclei...
Hasinger, G., Schartel, N., Komossa, S.
Recent XMM-Newton observations of the high-redshift, lensed, broad absorption line (BAL) quasi-stellar object APM 08279+5255, one of the most luminous objects in the universe, allowed the detection...
Hasinger, G., Schartel, N., Komossa, S.
Recent XMM-Newton observations of the high-redshift, lensed, broad absorption line (BAL) quasi-stellar object APM 08279+5255, one of the most luminous objects in the universe, allowed the detection...
Searching for X-ray Galaxy Clusters in the Zone of Avoidance (2000)
Boehringer, H., Schuecker, P., Komossa, S., Retzlaff, J., Reiprich, T. H., Voges, W.
Based on the ROSAT All-Sky Survey we are constructing a sample of the X-ray brightest galaxy clusters for cosmological studies. We have already completed the compilation of a sample of about 1000...
1E 0117.2-2837 and the NLR of Narrow-Line Seyfert 1 galaxies (2000)
Komossa, S., Grupe, D., Janek, M.
Based on photoionization calculations we present a study of the NLR emission line ratios of Narrow-line Seyfert 1 (NLS1) galaxies. In particular, we investigate the influence of different EUV -...
Properties of Warm absorbers in Narrow-Line Seyfert 1 galaxies (2000)
We present a study of the X-ray properties of several NLS1 galaxies, focusing on their warm absorbers. In the first part, we discuss properties of dusty and dust-free warm absorbers in NLS1s, and...
Boehringer, H., Voges, W., Huchra, J. P., McLean, B., Giacconi, R., Rosati, P., ...
In the construction of an X-ray selected sample of galaxy clusters for cosmological studies, we have assembled a sample of 495 X-ray sources found to show extended X-ray emission in the first...
X-ray absorption lines in the Seyfert 1 galaxy NGC 5548 discovered with Chandra-LETGS (2000)
Kaastra, J. S., Mewe, R., Liedahl, D. A., Komossa, S., Brinkman, A. C.
We present for the first time a high-resolution X-ray spectrum of a Seyfert galaxy. The Chandra-LETGS spectrum of NGC 5548 shows strong, narrow absorption lines from highly ionised species (the...
The warm absorber in IRAS 13349+2438: dusty or not? (1999)
Siebert, J., Komossa, S., Brinkmann, W.
IRAS13349+2438 was the first quasar suggested to host a warm absorber with internal dust. We obtained new HRI data for this object and derive constraints on the X-ray emitting region of...
The WC6 Wolf-Rayet star MLA 1159 in M31 and its ionization nebula BA 1-642 (1999)
Greiner, J., Tovmassian, G. H., Komossa, S., Rosado, M., Arrieta, A.
We report on optical imaging and spectroscopic observations of the Wolf-Rayet candidate star MLA 1159 and the surrounding ionization nebula BA 1-642 in the Andromeda Galaxy. Though both objects have...
Clues on the obscured active nucleus of NGC 1365 (1999)
Schulz, H., Komossa, S., Schmitz, C., Muecke, Anita
We have analyzed optical spectra (ESO-CASPEC) from the composite starburst-Seyfert galaxy NGC 1365 taken on the nucleus and the following positions (relative to nucleus): 2 arcsec N, 2 arcsec W; 2...
Clues on the obscured active nucleus of NGC 1365 (1999)
Schulz, H., Komossa, S., Schmitz, C., Muecke, Anita
We have analyzed optical spectra (ESO-CASPEC) from the composite starburst-Seyfert galaxy NGC 1365 taken on the nucleus and the following positions (relative to nucleus): 2 arcsec N, 2 arcsec W; 2...
Four new active galaxies with steep soft X-ray spectra (1995)
Greiner, J., Danner, R., Bade, N., Richter, G. A., Kroll, P., Komossa, S.
We have discovered four AGN in the ROSAT all-sky-survey data with very steep X-ray spectra. We apply several models to these X-ray spectra with emphasis on warm absorber models which give an adequate...