English

Infrared Imaging of SDSS Quasars: Implications for the Quasar K correction

Astrophysics 2009-11-13 v1

Abstract

We have imaged 45 quasars from the Sloan Digital Sky Survey (SDSS) with redshifts 1.85 < z < 4.26 in JHKs with the KPNO SQIID imager. By combining these data with optical magnitudes from the SDSS we have computed the restframe optical spectral indices of this sample and investigate their relation to quasar redshift. We find a mean spectral index of <alpha_o> = -0.55+/-0.42 with a large spread in values. We also find possible evolution of the form alpha_o = (0.148+/-0.068)z - (0.964+/-0.200)$ in the luminosity range -28.0 < M_i < -26.5. Such evolution suggests changes in the accretion process in quasars with time and is shown to have an effect on computed quasar luminosity functions.

Keywords

Cite

@article{arxiv.0809.0521,
  title  = {Infrared Imaging of SDSS Quasars: Implications for the Quasar K correction},
  author = {Julia Kennefick and Shelly Bursick},
  journal= {arXiv preprint arXiv:0809.0521},
  year   = {2009}
}

Comments

20 pages, 10 figures, 3 tables, accepted to the Astronomical Journal

R2 v1 2026-06-21T11:16:17.973Z