Analysis of interacting and isolated quasars
arXiv:1804.10219 · doi:10.1051/0004-6361/201629407
Abstract
The main goal of this study was to determine the effects on equivalent widths (EWs) of some spectral lines produced in the quasars by the presence of surrounding galaxies. To carry this out, a sample of 4663 quasars (QSOs) in the redshift range of 0.20 to 0.40 from the Sloan Digital Sky Survey--Data Release 7 was analyzed. Three QSO sub-samples were defined, taking into account the projected separations and radial velocity differences with neighboring galaxies. In this way, we utilized two sub-samples of QSOs with strong and weak galaxy interactions, with projected separations smaller than 70 kpc, and between 70 and 140 kpc, respectively, and with radial velocity differences less than \kms. These sub-samples were compared with isolated QSOs defined as having greater projected separations and radial velocity differences to the galaxies. From a statistical study of the EWs of relevant spectral lines in the QSOs, we show an increment of the EWs of about 20\% in the [OIII]4959,5007 lines and 7\% in H for QSOs with stronger galaxy interactions relative to the isolated QSOs. These results indicate that some line EWs of QSOs could be marginally influenced by the environment and that they are not affected by the emission of the host galaxy, which was estimated to be around 10\% of the total emission. Furthermore, in order to gain a better understanding of the origin of the H emission line, we performed broad and narrow line decomposition in 100 QSOs in the restricted Sint sub-sample and also 100 randomly selected QSOs in the Iso sub-sample. When these QSOs were compared, the narrow component remained constant whereas the broad component was incremented. Our results, which reveal slight differences in EWs of some emission lines, suggest that galaxy interactions with QSOs may affect the QSO activity.
arXiv commentAccepted for publication in the Astronomy & Astrophysics. 9 pages, 9 figures
References in corpus (31)
- Stellar population synthesis at the resolution of 2003
- The Sloan Digital Sky Survey: Technical Summary
- The Seventh Data Release of the Sloan Digital Sky Survey
- Unified Schemes for Radio-Loud Active Galactic Nuclei
- The Host Galaxies of AGN
- Spectroscopic Target Selection in the Sloan Digital Sky Survey: The Main Galaxy Sample
- The Second Data Release of the Sloan Digital Sky Survey
- The Sloan Digital Sky Survey Quasar Catalog V. Seventh Data Release
- Present-Day Growth of Black Holes and Bulges: the SDSS Perspective
- Quasars, their host galaxies, and their central black holes
- ANNz: estimating photometric redshifts using artificial neural networks
- The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
- Slicing Through Multicolor Space: Galaxy Redshifts From Broadband Photometry
- A Significant Population of Very Luminous Dust-Obscured Galaxies at Redshift z ~ 2
- Analysis of Systematic Effects and Statistical Uncertainties in Angular Clustering of Galaxies from Early SDSS Data
- Galaxy Pairs in the 2dF Survey I. Effects of Interactions in the Field
- The Sloan Digital Sky Survey quasar catalog: tenth data release
- Semi-empirical analysis of Sloan Digital Sky Survey galaxies: II. The bimodality of the galaxy population revisited
- Star Formation in Close Pairs Selected from the Sloan Digital Sky Survey
- The host galaxies of luminous quasars
- The Fueling and Evolution of AGN: Internal and External Triggers
- Quasar host galaxy star formation activity from multicolour data
- Broad Line Region Physical Conditions along the Quasar Eigenvector 1 Sequence
- The Small-Scale Environment of Quasars
- Tidally-Triggered Star Formation in Close Pairs of Galaxies 2: Constraints on Burst Strengths and Ages
- The AGN, Star-Forming, and Morphological Properties of Luminous IR-Bright/Optically-Faint Galaxies
- Photometric redshifts and K-corrections for Sloan Digital Sky Survey Seven Data Release
- Low redshift quasars in the SDSS Stripe 82. The host galaxies
- X-ray and multiwavelength view of NGC 4278. A LINER-Seyfert connection?
- Impact of an AGN featureless continuum on estimation of stellar population properties
- Spectral nuclear properties of NLS1 galaxies