S. Hämmerich

Tracking Down the Broadband Polarimetric Properties of PG 1553+113

R. Middei, Svetlana G. Jorstad, Alan P. Marscher, Ioannis Liodakis et autres

Abstract We report on a nine-month monitoring campaign of the blazar PG 1553+113, relying on three observations carried out in 2025 with the Imaging X-ray Polarimetry Explorer (IXPE) and supported by multiwavelength facilities. The source displayed pronounced variability across the electromagnetic spectrum, …

it, ru, gr, us, es, fr, de, pl, rs, fi, dk, ua, jp (code pays fourni par la source)

A Changing-Look Seyfert Discovered by eROSITA Reveals a Two-Component Broad-Line Region

Alex Markowitz, M. Krumpe, David Homan, B. Czerny et autres

Extreme sudden changes in the flow of accreting gas onto SMBHs manifest themselves via large-amplitude continuum variability and changes to broad Balmer emission profiles, driving changing-look AGN. X-ray flux monitoring with SRG/eROSITA revealed that in the Seyfert AGN HE 1237-2252 the soft …

pl, de, gb, ru, rs, Afrique du Sud, in, us (code pays fourni par la source)

Unveiling blazar synchrotron emission: a multiwavelength polarimetric study of HSP and LSP populations

Sara Capecchiacci, Ioannis Liodakis, R. Middei, Dawoon E. Kim et autres

Polarimetric properties of blazars allow us to put constraints on the acceleration mechanisms that fuel their powerful jets. By studying the multiwavelength polarimetric behaviour of high synchrotron peaked (HSP) and low synchrotron peaked (LSP) blazars, we aim to explore differences in their …

fr (code pays fourni par la source)

The first all-sky survey of star-forming galaxies with eROSITA

E. Kyritsis, A. Zezas, F. Haberl, P. Weber et autres

Context. In this work, we present the results from a study of X-ray normal galaxies, that is, galaxies not harbouring active galactic nuclei (AGN), using data from the first complete all-sky scan of the eROSITA X-ray survey (eRASS1) obtained with eROSITA on …

gr, de, us (code pays fourni par la source)

The eROSITA Final Equatorial Depth Survey (eFEDS)

K. Nandra, Sophia G. H. Waddell, Johannes Büchner, T. Dwelly et autres

Context. During its calibration and performance verification phase, the eROSITA instrument aboard the Spectrum-RG satellite performed a uniform wide-area X-ray survey of approximately 140 deg 2 , known as the eROSITA Final Equatorial Depth Survey (eFEDS). Aims. The primary aim of eFEDS …

de, us, it, gr, cl (code pays fourni par la source)

The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn

J. Wolf, M. Salvato, S. Belladitta, R. Arcodia et autres

Context. The Spektrum-Roentgen-Gamma (SRG)/extended Roentgen Survey with an Imaging Telescope Array (eROSITA) All-Sky Survey (eRASS) is expected to contain ∼100 quasars that emitted their light when the universe was less than a billion years old, that is, at z > 5.6. By …

eROSITA(eRASS1) study of the Canis Major overdensity: Developing a multi-wavelength algorithm for classifying faint X-ray sources

Sara Saeedi, Manami Sasaki, Jonathan Knıes, J. Robrade et autres

Using data from Roentgen Survey with an Imaging Telescope Array) on board Spektrum-Roentgen-Gamma (Spektr-RG, SRG) taken during the first all-sky survey (eRASS1), we performed the first X-ray classification and population study in the field of the Canis Major overdensity\,(CMa OD), which is …

de (code pays fourni par la source)

The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn

J. Wolf, M. Salvato, S. Belladitta, R. Arcodia et autres

The SRG/eROSITA All-Sky Survey (eRASS) is expected to contain ~100 quasars that emitted their light when the universe was less than a billion years old, i.e. at z>5.6. By selection, these quasars populate the bright end of the AGN X-ray luminosity function …

Shotglas

M. Latour, S. Hämmerich, M. Dorsch, U. Heber et autres

de, gb, nl, pt (code pays fourni par la source)

Probing the physical properties of the intergalactic medium using SRG/eROSITA spectra from blazars

Efraín Gatuzz, J. Wilms, S. Hämmerich, R. Arcodia

Most baryonic matter resides in the intergalactic medium (IGM). This diffuse gas is primarily composed of ionized hydrogen and helium and fills the space between galaxies. Observations of this environment are crucial for better understanding the physical processes in it. We present …

de, us (code pays fourni par la source)

The SRG/eROSITA all-sky survey

A. Merloni, G. Lamer, Teng Liu, M. E. Ramos-Ceja et autres

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 sky maps of an unprecedented depth. Here we present catalogues of both point-like and …

de, cn, gr, us, it, fr, at, nl (code pays fourni par la source)

TELAMON: Effelsberg monitoring of AGN jets with very-high-energy astroparticle emission

Florian Eppel, M. Kadler, J. Heßdörfer, P. Benke et autres

Aims.We introduce the TELAMON program which is using the Effelsberg 100-m telescope to monitor the radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, specifically TeV blazars and candidate neutrino-associated AGN. Here, we present and characterize our main sample …

de, us, ch, au, it, tw, jp, Afrique du Sud (code pays fourni par la source)