371 citations · 778 across the 23 of their papers we have counts for
24 papers
A large population of over-massive black hole quasars at z=0.3-0.8 revealed by eROSITA
Johannes Buchner, Isabelle Gauger, Qiaoya Wu +14
In most galaxies, the central black hole accounts for no more than a percent of the total mass in stars. Recently, however, extremely over-massive black holes with ratios of 10% ha…
Counterpart identification and classification for eRASS1 and characterisation of the AGN content
M. Salvato, J. Wolf, T. Dwelly +44
[abridged] Accurately accounting for the AGN phase in galaxy evolution requires a large, clean AGN sample. This is now possible with SRG/eROSITA. The public Data Release 1 (DR1, Ja…
The Average Soft X-ray Spectra of eROSITA Active Galactic Nuclei
Shi-Jiang Chen, Johannes Buchner, Teng Liu +16
Context. AGNs are strong X-ray emitters shaped by disk-corona interactions. The soft excess (0.5-2.0 keV) reveals key information about the "warm corona" bridging the disk and hot…
The eROSITA Final Equatorial Depth Survey (eFEDS): SDSS spectroscopic observations of X-ray sources
Catarina Aydar, Andrea Merloni, Tom Dwelly +45
We present one of the largest uniform optical spectroscopic surveys of X-ray selected sources to date that were observed as a pilot study for the Black Hole Mapper (BHM) survey. Th…
An X-ray flaring event and a variable soft X-ray excess in the Seyfert LCRS B040659.9-385922 as detected with eROSITA
S. Krishnan, A. G. Markowitz, M. Krumpe +13
Extreme continuum variability in AGNs can indicate extreme changes in accretion flows onto supermassive black holes. We explore the multiwavelength nature of a continuum flare in t…
Winds of change: the nuclear and galaxy-scale outflows and the X-ray variability of 2MASS 0918+2117
P. Baldini, G. Lanzuisi, M. Brusa +21
Powerful outflows from active galactic nuclei (AGN) can significantly impact the gas reservoirs of their host galaxies. However, it is still unclear how these outflows can propagat…
The SRG/eROSITA all-sky survey: Hard X-ray selected Active Galactic Nuclei
Sophia G. H. Waddell, J. Buchner, K. Nandra +12
The eROSITA instrument aboard the Spectrum Roentgen Gamma (SRG) satellite has performed its first all-sky survey between December 2019 and June 2020. This paper presents the result…
The eROSITA Final Equatorial Depth Survey (eFEDS): the hard X-ray selected sample
K. Nandra, S. G. H. Waddell, T. Liu +25
During its calibration and performance verification phase, the eROSITA instrument aboard the SRG satellite performed a uniform wide--area X-ray survey of approximately 140 deg$^{2}…
The SRG/eROSITA all-sky survey: First X-ray catalogues and data release of the western Galactic hemisphere
A. Merloni, G. Lamer, T. Liu +142
The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sk…
The eROSITA DR1 variability catalogue
Th. Boller, M. Salvato, J. Buchner +14
With its first All-Sky Survey (eRASS1), the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Spectrum-Roentgen-Gamma (SRG) mission has offered an unp…
A new discovery space opened by eROSITA: Ionised AGN outflows from X-ray selected samples
Blessing Musiimenta, Marcella Brusa, Teng Liu +21
In the context of an evolutionary model, the outflow phase of an Active Galactic Nuclei (AGN) occurs at the peak of its activity, once the central SMBH is massive enough to generat…
The eROSITA Final Equatorial Depth Survey (eFEDS): Complex absorption and soft excesses in hard X-ray--selected active galactic nuclei
Sophia G. H. Waddell, Kirpal Nandra, Johannes Buchner +14
Context. The soft excess, a surplus of X-ray photons above 2 keV with respect to a power law, is a feature of debated physical origin found in the X-ray spectra of many type-1 acti…
X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at z=6.56
Julien Wolf, Kirpal Nandra, Mara Salvato +14
This study aims at identifying luminous quasars at among X-ray-selected sources in the eROSITA Final Equatorial-Depth Survey (eFEDS) in order to place a lower limit on blac…
Collimation of the kiloparsec-scale radio jets in NGC 2663
Velibor Velović, M. D. Filipović, L. Barnes +25
We present the discovery of highly-collimated radio jets spanning a total of 355 kpc around the nearby elliptical galaxy NGC 2663, and the possible first detection of recollimation…
A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies: II. Iron emission and absorption
Sophia G. H. Waddell, Luigi C. Gallo
A sample of 22 narrow-line Seyfert 1 (NLS1) and 47 broad-line Seyfert 1 (BLS1) galaxies observed with Suzaku is used to examine the Fe K band properties of each group. Three differ…
The eROSITA Final Equatorial-Depth Survey (eFEDS): The AGN Catalogue and its X-ray Spectral Properties
Teng Liu, Johannes Buchner, Kirpal Nandra +23
Context: After the successful launch of the Spectrum-Roentgen-Gamma (SRG) mission in July 2019, eROSITA, the soft X-ray instrument aboard SRG, performed scanning observations of a…
Extreme ultra-soft X-ray variability in an eROSITA observation of the Narrow-Line Seyfert 1 Galaxy 1H 0707-495
Th. Boller, T. Liu, P. Weber +9
The ultra-soft narrow-line Seyfert 1 galaxy 1H 0707-495 is a well-known and highly variable active galactic nucleus (AGN), with a complex, steep X-ray spectrum, and has been studie…
A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies: I. X-ray spectral properties
Sophia G. H. Waddell, Luigi C. Gallo
A sample of narrow-line (NLS1) and broad-line Seyfert 1 (BLS1) galaxies observed with Suzaku is presented. The final sample consists of 22 NLS1s and 47 BLS1s, for a total of 69 AGN…
Uncovering the primary X-ray emission and possible starburst component in the polarized NLS1 Mrk 1239
Margaret Z. Buhariwalla, Sophia G. H. Waddell, Luigi C. Gallo +2
X-ray observations of the unique NLS1 galaxy Mrk 1239 spanning 18-years are presented. Data from XMM-Newton, Suzaku, Swift and NuSTAR are combined to obtain a broad-band, multi-epo…
Multi-epoch X-ray spectral analysis of the narrow-line Seyfert 1 galaxy Mrk 478
S. G. H. Waddell, L. C. Gallo, A. G. Gonzalez +2
A multi-epoch X-ray spectral and variability analysis is conducted for the narrow-line Seyfert 1 (NLS1) active galactic nucleus (AGN) Mrk 478. All available X-ray data from XMM-New…
The nature of the soft-excess and spectral variability in the Seyfert 1 galaxy Zw 229.015
S. Tripathi, S. G. H. Waddell, L. C. Gallo +2
We have carried out a systematic analysis of the nearby (z=0.0279) active galaxy Zw 229.015 using multi-epoch, multi-instrument and deep pointed observations with XMM-Newton, Suzak…
Nuclear spallation in active galaxies
L. C. Gallo, J. S. Randhawa, S. G. H. Waddell +3
A number of works point to the presence of narrow emission features at unusual energies in the X-ray spectra of active galactic nuclei (AGN) or to potentially low iron abundances a…
Evidence for an emerging disc wind and collimated outflow during an X-ray flare in the narrow-line Seyfert 1 galaxy Mrk 335
L. C. Gallo, A. G. Gonzalez, S. G. H. Waddell +13
A triggered 140 ks XMM-Newton observation of the narrow-line Seyfert 1 (NLS1) Mrk 335 in December 2015 caught the active galaxy at its lowest X-ray flux since 2007. The NLS1 is rel…
The changing source of X-ray reflection in the radio-intermediate Seyfert 1 galaxy III Zw 2
Adam G. Gonzalez, Sophia G. H. Waddell, Luigi C. Gallo
We report on X-ray observations of the radio-intermediate, X-ray bright Seyfert 1 galaxy, III Zw 2, obtained with XMM-Newton, Suzaku, and Swift over the past 17-years. The source b…