76 datasets found

We present a catalog of central engine properties, i.e., black hole mass (M_BH_) and accretion luminosity (L_disk_), for a sample of 1077 blazars detected with the Fermi Large...

In this work, we present the first results of the long-term high-cadence spectroscopic monitoring of 15 PG quasars with relatively strong FeII emission, as a part of a broader...

Optical time-domain astronomy has grown rapidly in the past decade, but the dynamic infrared sky is rarely explored. Aiming to construct a sample of mid-infrared outbursts in...

We report a timing analysis of near-infrared (NIR), X-ray, and submillimeter data during a 3 day coordinated campaign observing Sagittarius A. Data were collected at 4.5um with...

Under the hypothesis of gravitational redshift induced by a central supermassive black hole, and based on line widths and shifts of redward-shifted H{beta} and FeII broad...

The origin of jets is one of the most important issues concerning active galactic nuclei, yet it has remained obscure. In this work, we made use of information from emission...

Searches for electromagnetic counterparts of gravitational-wave signals have redoubled since the first detection in 2017 of a binary neutron star merger with a gamma-ray burst,...

We report the results of near-infrared spectroscopic observations of 37 quasars in the redshift range 6.3<z<=7.64, including 32 quasars at z>6.5, forming the largest...

We present optical follow-up imaging obtained with the Katzman Automatic Imaging Telescope, Las Cumbres Observatory Global Telescope Network, Nickel Telescope, Swope Telescope,...

While radio emission in quasars can be contributed to by a variety of processes (involving star-forming regions, accretion disk coronas and winds, and jets), the powering of the...

The massive black hole (BH) population in dwarf galaxies (M_BH_<~10^5^M_{sun}) can provide strong constraints on the origin of BH seeds. However, traditional optical searches...

We report the results of a multiyear spectroscopic and photometric monitoring campaign of two luminous quasars, PG0923+201 and PG1001+291, both located at the high-luminosity...

We measure a strong excess in the galaxy number density around PG1630+377, an extremely massive (MBH~109.7M{sun}) quasar at z=1.475, using near-infrared narrowband imaging. We...

The Super-Kamiokande detector can be used to search for neutrinos in time coincidence with gravitational waves detected by the LIGO-Virgo Collaboration (LVC). Both low-energy...

We constrained the progenitor masses for 169 supernova remnants (SNRs), eight historically observed supernovae (SNe), and the black hole formation candidate in NGC 6946, finding...

We present optical follow-up observation results of three binary black hole merger (BBH) events, GW190408_181802, GW190412, and GW190503_185404, which were detected by the...

We search for gravitational-wave transients associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the first part of the third observing run...

Supermassive black hole binaries (SMBHBs) should form frequently in galactic nuclei as a result of galaxy mergers. At subparsec separations, binaries become strong sources of...

We revisit the dependence of the covering factor (CF) of dust torus on physical properties of active galactic nuclei (AGNs) by taking into account an AGN polar dust emission....

We present StrayCats, a catalog of Nuclear Spectroscopic Telescope ARray (NuSTAR) stray light observations of X-ray sources. Stray light observations arise for sources...