Extragalactic peaked-spectrum radio sources at low frequencies
JR Callingham, RD Ekers, BM Gaensler… - The Astrophysical …, 2017 - iopscience.iop.org
We present a sample of 1483 sources that display spectral peaks between 72 MHz and 1.4
GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array …
GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array …
Improving blazar redshift constraints with the edge of the Ly α forest: 1ES 1553+ 113 and implications for observations of the WHIM
Blazars are some of the brightest ultraviolet (UV) and X-ray sources in the sky and are
valuable probes of the elusive warm-hot intergalactic medium (WHIM; T≃ 105–107 K) …
valuable probes of the elusive warm-hot intergalactic medium (WHIM; T≃ 105–107 K) …
On the reliability of microvariability tests in quasars
JA De Diego - The Astronomical Journal, 2014 - iopscience.iop.org
Microvariations probe the physics and internal structure of quasars. Unpredictability and
small flux variations make this phenomenon elusive and difficult to detect. Variance-based …
small flux variations make this phenomenon elusive and difficult to detect. Variance-based …
Evidence of underdeveloped torus and broad-line region of weak emission line quasars based on their spectral energy distribution
To unravel the dominant cause of the weak emission line in a subset of optically selected
radio-quiet 'weak emission line quasars'(WLQs), we have investigated the possibility of an …
radio-quiet 'weak emission line quasars'(WLQs), we have investigated the possibility of an …
Intra-night optical variability of γ-ray detected narrow-line Seyfert1 galaxies
V Ojha, H Chand - Monthly Notices of the Royal Astronomical …, 2021 - academic.oup.com
We report the first attempt to systematically characterize intra-night optical variability (INOV)
of the rare and enigmatic subset of narrow-line Seyfert1 galaxies (NLSy1s), which is marked …
of the rare and enigmatic subset of narrow-line Seyfert1 galaxies (NLSy1s), which is marked …
The Weakness of Soft X-Ray Intensity: Possible Physical Reason for Weak-line Quasars
Weak-line quasars (WLQs) are a notable group of active galactic nuclei (AGNs) that show
unusually weak UV lines even though their optical-UV continuum shapes are similar to …
unusually weak UV lines even though their optical-UV continuum shapes are similar to …
Intranight optical variability of radio-quiet weak emission line quasars–III
This is continuation of our programme to search for the elusive radio-quiet BL Lacs, by
carrying out a systematic search for intranight optical variability (INOV) in a subset of 'weak …
carrying out a systematic search for intranight optical variability (INOV) in a subset of 'weak …
Narrow absorption line variability in repeat quasar observations from the Sloan Digital Sky Survey
TL Hacker, RJ Brunner, BF Lundgren… - Monthly Notices of the …, 2013 - academic.oup.com
We present the results from a time domain study of absorption lines detected in quasar
spectra with repeat observations from the Sloan Digital Sky Survey Data Release 7 (SDSS …
spectra with repeat observations from the Sloan Digital Sky Survey Data Release 7 (SDSS …
Multi-epoch intranight optical monitoring of eight radio-quiet BL Lac candidates
P Kumar, CS Stalin, H Chand… - Monthly Notices of …, 2017 - academic.oup.com
For a new sample of eight weak-line quasars (WLQs) we report a sensitive search in 20
intranight monitoring sessions, for blazar-like optical flux variations on hour-like and longer …
intranight monitoring sessions, for blazar-like optical flux variations on hour-like and longer …
Intranight optical variability of radio-quiet weak emission line quasars–IV
We report an extension of our programme to search for radio-quiet BL Lac candidates using
intranight optical variability (INOV) as a probe. The present INOV observations cover a well …
intranight optical variability (INOV) as a probe. The present INOV observations cover a well …