395 citations · 5.4k across the 130 of their papers we have counts for
47 papers · 1 filter
Supermassive Black Hole Winds in X-rays -- SUBWAYS. VI. Interplay between the soft X-ray excess and ultra-fast outflows
V. E. Gianolli, P-O. Petrucci, S. Bianchi +42
We present a broadband, multiwavelength study of the interplay between the soft X-ray excess (SE), ultra-fast outflows (UFOs), and warm absorbers (WAs) in 21 active galactic nuclei…
Insights into density and location diagnostics of photo-ionized outflows in X-ray binaries
Sharon Mitrani, Ehud Behar
The population of meta-stable levels is key to high precision density diagnostics of astrophysical plasmas. In photo-ionized plasmas, density is used to infer the distance from the…
A re-emerging bright soft-X-ray state of the changing-look Active Galactic Nucleus 1ES~1927+654: a multi-wavelength view
Ritesh Ghosh, Sibasish Laha, Eileen Meyer +24
1ES1927+654 is a nearby active galactic nucleus that has shown an enigmatic outburst in optical/UV followed by X-rays, exhibiting strange variability patterns at timescales of mont…
Absorption of GRB X-ray Afterglows by The Missing Baryons: Confronting Observations with Cosmological Simulations
Matan Grauer, Ehud Behar
A large fraction of the baryons at low redshift are undetected, and likely reside in the tenuous, hot intergalactic medium (IGM). One way to probe the missing baryons is through th…
Science with a small two-band UV-photometry mission I: Mission description and follow-up observations of stellar transients
N. Werner, J. Řípa, C. Thöne +33
This is the first in a collection of three papers introducing the science with an ultra-violet (UV) space telescope on an approximately 130~kg small satellite with a moderately fas…
A NICER viewing angle on the accretion stream of Vela X-1
Roi Rahin, Ehud Behar
Vela X-1 is the archetypical eclipsing high-mass X-ray binary, composed of a neutron star (NS) accreting the B-star wind. It was observed by nearly all X-ray observatories, often m…
Supermassive Black Hole Winds in X-rays: SUBWAYS. II. HST UV spectroscopy of winds at intermediate redshifts
M. Mehdipour, G. A. Kriss, M. Brusa +35
We present a UV spectroscopic study of ionized outflows in 21 active galactic nuclei (AGN), observed with the HST. The targets of the SUBWAYS sample were selected with the aim to p…
Supermassive Black Hole Winds in X-rays -- SUBWAYS. I. Ultra-fast outflows in QSOs beyond the local Universe
G. A. Matzeu, M. Brusa, G. Lanzuisi +48
We present a new X-ray spectroscopic study of luminous () active galactic nuclei (AGNs) at intermed…
Shocks in the outflow of the RS Oph 2021 eruption observed with X-ray gratings
Marina Orio, Ehud Behar, Juan Luna +9
The 2021 outburst of the symbiotic recurrent nova RS Oph was observed with the Chandra High Energy Transmission Gratings (HETG) on day 18 after optical maximum and with XMM-Newton…
Detection of an Unidentified Soft X-ray Emission Feature in NGC 5548
Liyi Gu, Junjie Mao, Jelle S. Kaastra +17
NGC~5548 is an X-ray bright Seyfert 1 active galaxy. It exhibits a variety of spectroscopic features in the soft X-ray band, including in particular the absorption by the AGN outfl…
Ionization Distributions in Outflows of Active Galaxies: Universal Trends and Prospect of Future XRISM Observations
Noa Keshet, Ehud Behar
The physics behind the ionization structure of outflows from black holes is yet to be fully understood. Using archival observations with the Chandra\HETG gratings over the past two…
Hard-X-ray-selected Active Galactic Nuclei -- II. Spectral Energy Distributions in the 5-45 GHz domain
Francesca Panessa, Elia Chiaraluce, Gabriele Bruni +7
A wide-frequency radio study of Active Galactic Nuclei (AGN) is crucial to evaluate the intervening radiative mechanisms responsible for the observed emission and relate them with…
Transient obscuration event captured in NGC 3227 III. Photoionization modeling of the X-ray obscuration event in 2019
Junjie Mao, J. S. Kaastra, M. Mehdipour +16
A growing number of transient X-ray obscuration events in type I AGN suggest that our line-of-sight to the central engine is not always free. Multiple X-ray obscuration events have…
NICER monitoring of supersoft X-ray sources
M. Orio, K. Gendreau, M. Giese +9
We monitored four supersoft sources - two persistent ones, CAL 83 and MR Vel, and the recent novae YZ Ret (Nova Ret 2020) and V1674 Her (Nova Her 2021) - with NICER. The two persis…
A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states
Sibasish Laha, Eileen Meyer, Agniva Roychowdhury +17
The nearby type-II AGN 1ES1927+654 went through a violent changing-look (CL) event beginning December 2017 during which the optical and UV fluxes increased by four magnitudes over…
Nova LMC 2009a as observed with XMM-Newton, compared with other novae
Marina Orio, Andrej Dobrotka, Ciro Pinto +9
We examine four high resolution reflection grating spectrometers (RGS) spectra of the February 2009 outburst of the luminous recurrent nova LMC 2009a. They were very complex and ri…
Modeling Magnetic Disk-Wind State Transitions in Black Hole X-ray Binaries
Keigo Fukumura, Demosthenes Kazanas, Chris Shrader +3
We analyze three prototypical black hole (BH) X-ray binaries (XRBs), \4u1630, \gro1655\ and \h1743, in an effort to systematically understand the intrinsic state transition of the…
Canonical X-Ray Fluorescence Line Intensities as Column Density Indicators
Roi Rahin, Ehud Behar
X-ray line fluorescence is ubiquitous around powerful accretion sources, namely active galactic nuclei and X-ray binaries. The brightest and best-studied line is the Fe K line a…
Chandra High Energy Transmission Gratings Spectra of V3890 Sgr
Marina Orio, Jeremy J. Drake, Jan-Uwe Ness +13
The recurrent nova (RN) V3890 Sgr was observed during the 7th day after the onset of its most recent outburst, with the Chandra ACIS-S camera and High Energy Transmission Gratings…
Simultaneous Millimeter-wave and X-ray monitoring of the Seyfert Galaxy NGC 7469
Ehud Behar, Shai Kaspi, Gabriel Paubert +6
We report on daily monitoring of the Seyfert galaxy NGC 7469, around 95 GHz and 143 GHz, with the IRAM 30 m radio telescope, and with the Swift X-Ray and UV/Optical telescopes, ove…
Cosmological evolution of the absorption of -ray burst X-ray afterglows
Roi Rahin, Ehud Behar
X-ray absorption of -ray burst (GRB) afterglows is prevalent yet poorly understood. X-ray derived neutral hydrogen column densities () of GRB X-ray afterglows show an…
X-Ray Spectrum of RBS 315: Absorption or Intrinsic Curvature
Sivan Ben Haim, Ehud Behar, Richard F. Mushotzky
X-ray absorption of high-redshift quasars is enigmatic, because it remains unclear where in the universe the absorbing gas is. If absorption occurs near the high-z host, it could h…
Evidence for Radiation Pressure Compression in the X-ray Narrow Line Region of Seyfert galaxies
Stefano Bianchi, Matteo Guainazzi, Ari Laor +2
The observed spatial and kinematic overlap between soft X-ray emission and the Narrow Line Region (NLR) in obscured Active Galactic Nuclei (AGN) yields compelling evidence that rel…
Photoionized emission and absorption features in the high-resolution X-ray spectra of NGC 3783
Junjie Mao, M. Mehdipour, J. S. Kaastra +14
Our Swift monitoring program triggered two joint XMM-Newton, NuSTAR and HST observations on 11 and 21 December 2016 targeting NGC 3783, as its soft X-ray continuum was heavily obsc…