Compiled quasar catalog from LAMOST DR1 艾艳丽 Department of Astronomy, Peking University Collaborators : Xuebing Wu, Jinyi Yang, Feige Wang, Jianguo Wang, Xiaoyi Dong and LEGAS team LAMOST 用户培训会 兴隆 2014.07.02

From Fan, X. 2014, Xian

quasar selection point source contaminations are ≈100, million stars quasar selection：select candidates then with optical spectra confirmation and redshift measurement how to select the quasar candidates based on observed properties

unification model and observed spectra Broad permitted lines: Ha, Hb Urry & Padovani, 1995 Narrow lines only

Similar quasar spectra Characterize by featureless continuum and series emission lines Remarkably similar from one quasar to another, compared to galaxy and stars composite spectra at redshift 0.04---4. Vanden Berk et al. 2001

SDSS photometric system Richards et al. 2006

Quasar selection I ≈16,000 quasars found by SDSS based on multi-color optical selection (UV-excess) Star quasar Fan et al. 1999

quasar selection -- I low completeness at redshift 2 –3 as optical colors of quasars similar to those of stars low completeness to improve selection completeness variability selection( Butler 2011) combined optical—infrared color ----- LAMOST quasar selection Richards et al. 2006

Quasar selection -- II Optical– infrared color selection ( K-band excess) Unreddened QSO z=3 Early K star Reddened QSO z=3 Early M star Maddox et al. 2008

Quasar selection III SDSS_UKIDSS SDSS_WISE QSO z < 2.2 Wu 2010 Wu 2012

LAMOST quasar candidates LEGAS team Mostly from SDSS-UKIDSS SDSS-WISE Partly from X-ray, radio, and other selections

Observed quasar candidates ≈80,000 observed in pilot survey and first year of regular survey ≈60,000 classified as ‘unknown’ with featureless Magnitude distribution of ‘unknown’ “unknown”

≈5000 identified QSOs Lines move in cross-over between blue and red channel

≈ 3000 covered by SDSS DR10 possible emission line variation continuum variation but “should be carful”

visually checking again For the ≈2000 newly identified quasars Visually checked again and double checked independently by numbers of our group ≈600 are misclassified as quasar by pipeline visually check redshift and correct some of them for the ≈1400 quasars

≈1400 new quasars identified Z--Mi distribution

Median S/N ratio of emision lines

Emission line fitting and measurements ≈1000 with high enough S/N for spectra modelling

Continuum flux estimation with SDSS photometry use SDSS ugriz photometry and quasar continuum and emission line template

Black hole mass estimation Black hole mass distribution

Optical –infrared color of the quasar mostly from SDSS-UKIDSS, SDSS-WISE selection

more to do ≈40 X-ray source matched with XMM-Newton ≈100 radio source matched with FIRST ≈20 with repeated LAMOST spectra special quasar identified, such as, double-peaked quasar, broad-absorption line quasar

double-peaked quasar

Broad absorption quasar

谢谢