2016LAMOST July 13 142016 LAMOST XueBing WU KIAADo

2016年LAMOST用户培训会, 北京，July. 13 -14，2016 LAMOST 类星体巡天吴学兵 Xue-Bing WU (KIAA/Do. A, Peking University) On behalf of LEGAS (LAMOST Extragalactic Survey) working Group

What is a Quasar? "Twinkle, twinkle quasi-star Biggest puzzle from afar How unlike the other ones Brighter than a billion suns. Twinkle, twinkle quasi-star How I wonder what you are. " George Gamow, "Quasar " 1964. George Gamow coined the above in 1964 to commemorate the discovery of the first quasar, 3 C 273, in 1963 by Hazard and Schmidt. Cyril Hazard supplied the accurate radio position from Parkes lunar occultations (Hazard et al. 1963), and Maarten Schmidt provided the optical spectroscopy and redshift from the 200 -inch telescope in California (Schmidt 1963).

SDSS类星体选源 SDSS quasar selection (Richards et al. 2002) A: Low-z quasars: i<19. 1; UVX B: High-z quasars: i<20. 2; griz selection C: Radio quasars: i<19. 1; point sources

SDSS-UKIDSS quasar selection (Wu & Jia 2010, MNRAS) For z< 4 QSO For z< 5 QSO A completeness test with 700 radio-selected SDSS-UKIDSS quasars

SDSS-WISE quasar selection (Wu et al. 2012, AJ) quasar star Completeness check with radio quasars

LAMOST quasar survey • Began pilot survey in October 2011 and regular survey in September 2012 • Regular survey in five years (20122017) – LAMOST Extragalactic Survey (LEGAS) • DR 1 contains spectra taken before June 2013 • DR 2 contains spectra taken between Sep 2013 and June 2014 • DR 3 contains spectra taken between Sep 2014 and June 2015 2021 -03 -06 13

Quasar candidate selections • Point-sources in SDSS DR 9 and imag<20 • Optical-infrared color-color selections: – SDSS/UKIDSS: Y-K > 0. 46(g-z) + 0. 82 or J-K > 0. 45(i-Y 0. 366) (Wu & Jia 2010, MNRAS) – SDSS/WISE: w 1 -w 2>0. 57 or z-w 1>0. 66(g-z)+2. 01 (Wu et al. 2012, AJ) • Data-mining selections: – Support vector machine (SVM) classifiers (Peng et al. 2012) – Extreme deconvolution method (XDQSO, Bovy et al. 2011) – Kernel density estimator (KDE, Richards et al. 2009) • Supplemented via multi-wavelength (optical-X-ray/radio) data matching: – Objects with SDSS photometry in the X-ray sources of XMMNewton, Chandra, ROSAT and radio sources in FIRST (Becker et al. 1995), NVSS 2021 -03 -06 14

Results of DR 1 (Ai et al. 2016, AJ, 151, 24) 3921 quasars, 1180 new 2021 -03 -06 15

Results of DR 2 Observed 8839 QSOs 2852 New 1494 Known 1329 Unknowns 5987 NQSO New Known 29 664 927 QSO 5401 New QSO 2766 Others 1005 New 608 2021 -03 -06 Known 389 Unknown 4396 NQSO 8 LAMOST user meeting 16

Results of DR 3 Observed 18755 QSOs 6354 New 2219 Known 4078 Unknowns 12401 NQSO New Known Unknown 57 >1805 2893 ? >11459 QSO >4230 New QSO Others 506 New 206 2021 -03 -06 Known 258 NQSO 42 LAMOST user meeting 17

LAMOST Quasar Redshift Distribution 2021 -03 -06 LAMOST user meeting 18

LAMOST quasar sky coverage (observed before June 2015) 20374 quasars observed, >8176 new quasars (994 from Huo et al. in M 31/M 33) 2021 -03 -06 LAMOST user meeting 19