Monitoring Broad Absorption-Line Quasar Variability

Simple item page
dc.contributor.advisorHall, Patrick B.
dc.creatorRogerson, Jesse Aaron
dc.date.accessioned2016-09-20T18:53:17Z
dc.date.available2016-09-20T18:53:17Z
dc.date.copyright2016-04-18
dc.date.issued2016-09-20
dc.date.updated2016-09-20T18:53:17Z
dc.degree.disciplinePhysics And Astronomy
dc.degree.levelDoctoral
dc.degree.namePhD - Doctor of Philosophy
dc.description.abstractWinds generated by an accreting super massive black hole may provide feedback to the host galaxy and offer an explanation for the co-evolution of galaxies with their super massive black holes that has been reported in the literature. Some outflows are manifested as broad absorption line (BAL) troughs in quasar spectra, and are measured at velocities as high as 60, 000 km s 1 at ultra-violet wavelengths. These BAL troughs have been observed to vary on both long (years) and short (weeks) rest-frame time-scales and can emerge in a quasar that had none, or disappear completely. By monitoring the variability of absorption in BAL quasars, constraints can be placed on outflow models and the structure of quasars in general. In this study, we isolate a set of quasars that exhibit emergent C iv BALs in their spectra, by comparing archival data in the SDSS Data Release 7 to the BOSS Data Release 9 and 10. After visually defining a set of emergent BALs, follow-up observations were obtained with the Gemini Observatory for 105 quasars. BALs were formally detected in all but two of the quasars in the dataset, and we report 219 absorption complexes in the entire set. After a BAL has emerged, we find it is equally likely to continue increasing as it is to start decreasing in a subsequent observation. Based on the range of time between our observations, this indicates the coherence time-scale of BALs is less than 100 days. There is a strong signal of coordinated variability among two troughs in the same quasar. Further, coordination is stronger if the velocity separation between the two troughs is smaller. We conclude the variability is likely due to changes in the ionizing flux incident on the absorbing cloud, which agrees with the results of Filiz Ak et al. (2013). In this work we also test two competing models of BAL variability (bulk motion and ionization changes) in the context of a case study of the quasar SDSS J023011.28+005913.6, which had two high-velocity emergent troughs. Both models yield plausible results.
dc.identifier.urihttp://hdl.handle.net/10315/32316
dc.language.isoen
dc.rightsAuthor owns copyright, except where explicitly noted. Please contact the author directly with licensing requests.
dc.subjectAstronomy
dc.subject.keywordsQuasar
dc.subject.keywordsSupermassive black hole
dc.subject.keywordsAccretion
dc.subject.keywordsAbsorption
dc.titleMonitoring Broad Absorption-Line Quasar Variability
dc.typeElectronic Thesis or Dissertation

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Rogerson_Jesse_A_2016_PHD.pdf
Size:
5.75 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 2 of 2
No Thumbnail Available
Name:
license.txt
Size:
1.83 KB
Format:
Plain Text
Description:
Download
No Thumbnail Available
Name:
YorkU_ETDlicense.txt
Size:
3.38 KB
Format:
Plain Text
Description:
Download

Collections

Physics and Astronomy

All items in the YorkSpace institutional repository are protected by copyright, with all rights reserved except where explicitly noted.