Results 21 to 30 of about 2,579,062 (253)
LEGO: A 3 mm molecular line study covering 100 pc of one of the most actively star-forming portions in the Milky Way [PDF]
EPJ Web of Conferences, 2022 The current generation of high-sensitivity (sub)mm-telescopes such as the IRAM-30m and NOEMA have allowed the emission from molecular lines to become a major tool for studying the physical, kinematic and chemical properties of extragalactic systems ...
Barnes Ashley +2 more
doaj +1 more source
A New Statistical Approach to the Optical Spectral Variability in Blazars
Galaxies, 2016 We present a spectral variability study of a sample of about 25 bright blazars, based on optical spectroscopy. Observations cover the period from the end of 2008 to mid 2015, with an approximately monthly cadence.
Jose A. Acosta-Pulido +3 more
doaj +1 more source
Accretion Disk Structure and Kinematics of the Broad Line Regions in Selected AGN
Open Astronomy, 2011 Broad emission line regions in AGN are connected with the outer layers of accretion disks. This has been shown by means of line variability studies of individual AGN as well as line profile studies of AGN samples.
Kollatschny W., Zetzl M.
doaj +1 more source
Variability of Double-Peaked Emission Lines in AGNs as a Probe of the Broad-Line Region Structure
Open Astronomy, 2011 We demonstrate that the disk-wind model for the broad-line region (BLR) can explain the variability from single-peaked to double-peaked emission line (DPEL) profiles observed in some active galactic nuclei (AGNs) and can produce realistic single-peaked ...
Flohic Hélène M. L. G.
doaj +1 more source
SPECTRAL AND PHOTOMETRIC STUDIES OF MRK6 AND MRK1040 IN THE OPTICAL RANGE
Eurasian Physical Technical JournalThis paper is dedicated to the study of variability in active galactic nuclei, which play a key role in understanding the physical processes occurring in their central regions.
S.A. Shomshekova +5 more
doaj +1 more source
EMISSION LINE GALAXIES IN CLUSTERS [PDF]
, 2006 At the present epoch, clusters of galaxies are known to be a hostile environment for emission-line galaxies, which are more commonly found in low density regions outside of clusters. In contrast, going to higher redshifts the population of emission-line galaxies in clusters becomes progressively more conspicuous, and large numbers of star-forming late ...
openaire +2 more sources
Open Astronomy, 2012 AG Dra is a classical symbiotic star that undergoes major outbursts at intervals between 12-15 years. We present spectroscopic observations of four emission lines (Hα, Hβ, He II 4686 Å, Raman scattered OVI 6825 Å) before, during and after the major ...
Leedjärv L., Burmeister M.
doaj +1 more source
Frontiers in Astronomy and Space Sciences, 2018 Here we investigate the connection of broad emission line shapes and continuum light curve variability time scales of type-1 Active Galactic Nuclei (AGN).
Edi Bon +4 more
doaj +1 more source
Broad line emission from iron K- and L-shell transitions in the active galaxy 1H 0707-495
, 2009 Since the 1995 discovery of the broad iron K-line emission from the Seyfert galaxy MCG-6-30-15 (ref. 1), broad iron K lines have been found in emission from several other Seyfert galaxies, from accreting stellar-mass black holes and even from accreting ...
T. Boller +70 more
core +1 more source
Spectral and Photometric Studies of NGC 7469 in the Optical Range
UniverseThe galaxy NGC 7469 is a bright infrared source with an active galactic nucleus (AGN) and an intense star-forming region with a radius of approximately 500 parsecs, where the star formation rate is estimated to be 20–50 M⊙yr−1.
Saule Shomshekova +5 more
doaj +1 more source