QSOs - some studies are no more luminous than Markarian...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
QSOs : It was hard enough to tell that they were in galaxies, much less surrounded by others. Imaging from Mauna Kea has been extremely suggestive, with Hutchings and Campbell 1983 (Nature 303, 984) claiming that 30% of QSOs with z < 0.6 show evidence of interactions. Spectroscopy by Stockton (1979 IAU Symp. 92, 89) and Heckman et al. (1984 AJ 89, 958) confirms the association of these galaxies in redshift, and Stockton 1982 (ApJ 257, 33) has shown that many of the companions have their own low-luminosity active nuclei. Further individual systems have been studied by, for example, Shara et al 1985 (ApJ 246, 339; 4C 18.68), Yee and Green 1987 (AJ 94, 618; PG 1613+658), and Vader et al 1987 (AJ 94, 847; IRAS 00275-2359). Be careful in putting the statistical studies together; many of the "QSOs" in
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: some studies are no more luminous than Markarian Seyferts, so that it is not clear which problem is being addressed. Calling the Sun a quasar doesn't answer the quasar-physics problem. Anyway, as was long expected, HST results have added considerably to our understanding. Most QSO host galaxies have compact companions within tens of kpc (Bahcall et al. 1995 ApJ 450, 486, Disney et al. 1995 Nature 376, 150), a result which was foreshadowed by Stockton's 1982 paper. This fraction is by now the most striking correlation of nuclear activity and galaxy interactions. Some of these companions are seen in this montage of HST images, from rather luminous normal companions to the very close, compact companions of PKS 1302-102 and PKS 2349-013....
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern