1,401 datasets found

The 2021 Event Horizon Telescope observations resolve the innermost jet region of the blazar 3C 279 with unprecedented detail. The reconstructed images consistently reveal a...

We present the VST ATLAS Quasar Survey, consisting of ~1229000 quasar (QSO) candidates with 16 < g < 22.5 over ~4700 deg^2^. The catalogue is based on VST ATLAS+NEOWISE...

Active galactic nuclei (AGNs) are known to exhibit stochastic variability across a wide range of timescales and wavelengths. AGN flares are extreme outbursts that deviate from...

We analyze variability in 15-season optical lightcurves from the doubly imaged lensed quasar SDSS J165043.44+425149.3, comprising five seasons of monitoring data from the...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory. Chandra was formerly known as AXAF, the Advanced X-ray Astrophysics Facility, but renamed by...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory and one of NASA"s Great Observatories. Chandra was formerly known as AXAF, the Advanced X-ray...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory and one of NASA"s Great Observatories. Chandra was formerly known as AXAF, the Advanced X-ray...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory. Chandra was formerly known as AXAF, the Advanced X-ray Astrophysics Facility, but renamed by...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory. Chandra was formerly known as AXAF, the Advanced X-ray Astrophysics Facility, but renamed by...

The Chandra X-ray Observatory Data Archive provides a reference survey via the HiPS protocol. For detailed information on the Chandra Observatory and datasets see:...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory and one of NASA"s Great Observatories. Chandra was formerly known as AXAF, the Advanced X-ray...

We present a systematic search for changing-look (CL) quasars at high redshift z>0.9 by crossmatching the spectroscopic data sets from the Dark Energy Spectroscopic...

We introduce J-HERTz (J-PLUS Heritage Exploration of Radio Targets at z<5), a new multiwavelength catalog that combines optical narrowband photometry from J-PLUS, infrared...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory. Chandra was formerly known as AXAF, the Advanced X-ray Astrophysics Facility, but renamed by...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory and one of NASA"s Great Observatories. Chandra was formerly known as AXAF, the Advanced X-ray...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory. Chandra was formerly known as AXAF, the Advanced X-ray Astrophysics Facility, but renamed by...

The Chandra X-ray Observatory is the U.S. follow-on to the Einstein Observatory. Chandra was formerly known as AXAF, the Advanced X-ray Astrophysics Facility, but renamed by...

Polarization observations at millimeter wavelengths can be used to study magnetized plasma in jets launched by supermassive black holes. We used multiband Atacama Large...

Heavily reddened quasars (HRQs) are luminous, dust-obscured broad-line quasars thought to trace a short-lived phase of intense black hole growth and feedback. Previous studies...

How does the host galaxy morphology influence a central quasar or vice versa? We address this question by measuring the asymmetries of 2424 SDSS quasar hosts at 0.2 < z <...