Browsing by Author "Hennessy, GS"

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    An initial survey of white dwarfs in the Sloan Digital Sky Survey
    (2003) Harris, HC; Liebert, J; Kleinman, SJ; Nitta, A; Anderson, SF; Knapp, GR; Krzesinski, J; Schmidt, G; Strauss, MA; Berk, DV; Eisenstein, D; Hawley, S; Margon, B; Munn, JA; Silvestri, NM; Smith, JA; Szkody, P; Collinge, MJ; Dahn, CC; Fan, XH; Hall, PB; Schneider, DP; Brinkmann, J; Burles, S; Gunn, JE; Hennessy, GS; Hindsley, R; Ivezic, Z; Kent, S; Lamb, DQ; Lupton, RH; Nichol, RC; Pier, JR; Schlegel, DJ; SubbaRao, M; Uomoto, A; Yanny, B; York, DG
    An initial assessment is made of white dwarf and hot subdwarf stars observed in the Sloan Digital Sky Survey. In a small area of sky ( 190 square degrees), observed much like the full survey will be, 269 white dwarfs (WDs) and 56 hot subdwarfs are identified spectroscopically where only 44 white dwarfs and five hot subdwarfs were known previously. Most are ordinary DA ( hydrogen atmosphere) and DB ( helium) types. In addition, in the full survey to date, a number of WDs have been found with uncommon spectral types. Among these are blue DQ stars displaying lines of atomic carbon; red DQ stars showing molecular bands of C-2 with a wide variety of strengths; DZ stars where Ca and occasionally Mg, Na, and/or Fe lines are detected; and magnetic WDs with a wide range of magnetic field strengths in DA, DB, DQ, and ( probably) DZ spectral types. Photometry alone allows identification of stars hotter than 12,000 K, and the density of these stars for 15 < g < 20 is found to be similar to2.2 deg(-2) at Galactic latitudes of 29degrees - 62degrees. Spectra are obtained for roughly half of these hot stars. The spectra show that for 15 < g < 17, 40% of hot stars are WDs, and the fraction of WDs rises to similar to90% at g = 20. The remainder are hot sdB and sdO stars.
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    Broad absorption line quasars in the Sloan Digital Sky Survey with VLA first radio detections
    (2001) Menou, K; Vanden Berg, DE; Kim, RSJ; Knapp, GR; Richards, GT; Strateva, I; Fan, XH; Gunn, JE; Hall, PB; Heckman, T; Krolik, J; Lupton, RH; Schneider, DP; York, DG; Anderson, SF; Bahcall, NA; Brinkmann, J; Brunner, R; Csabai, I; Fukugita, M; Hennessy, GS; Kunszt, PZ; Lamb, DQ; Munn, JA; Nichol, RC; Szokoly, GP
    We present 13 broad absorption line (BAL) quasars, including 12 new objects, identified in the Sloan Digital Sky Survey (SDSS) and matched within 2 " to sources in the FIRST radio survey catalog. The surface density of this sample of radio-detected BAL quasars is 4.5 +/- 1.2 per 100 deg(2), i.e., approximately 4 times as high as previously found by the shallower FIRST Bright Quasar Survey (FBQS). A majority of these radio-detected BAL quasars are moderately radio-loud objects. The fraction of BAL quasars in the entire radio quasar sample, 4.8% +/- 1.3%, is comparable to the fraction of BAL quasars among the SDSS optical quasar sample (ignoring selection effects). We estimate that the true fraction of BAL quasars (mostly "HiBALs") in the radio sample is 9.2% +/- 2.6%, once selection effects are accounted for. We caution that the absorption troughs of four of the 13 radio-detected quasars considered do not strictly satisfy the standard BALnicity criteria. One or possibly two of the new radio-detected BAL quasars are of the rare "FeLoBAL" type. BAL quasars are generally redder than the median SDSS quasar at the same redshift.
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    Composite quasar spectra from the Sloan Digital Sky Survey
    (2001) Vanden Berk, DE; Richards, GT; Bauer, A; Strauss, MA; Schneider, DP; Heckman, TM; York, DG; Hall, PB; Fan, XH; Knapp, GR; Anderson, SF; Annis, J; Bahcall, NA; Bernardi, M; Briggs, JW; Brinkmann, J; Brunner, R; Burles, S; Carey, L; Castander, FJ; Connolly, AJ; Crocker, JH; Csabai, I; Doi, M; Finkbeiner, D; Friedman, S; Frieman, JA; Fukugita, M; Gunn, JE; Hennessy, GS; Ivezic, Z; Kent, S; Kunszt, PZ; Lamb, DQ; Leger, RF; Long, DC; Loveday, J; Lupton, RH; Meiksin, A; Pier, JR; Pope, A; Rockosi, CM; Schlegel, DJ; Siegmund, WA; Smee, S; Snir, Y; Stoughton, C; Stubbs, C; SubbaRao, M; Szalay, AS; Szokoly, GP; Tremonti, C; Uomoto, A; Waddell, P; Yanny, B; Zheng, W
    We have created a variety of composite quasar spectra using a homogeneous data set of over 2200 spectra from the Sloan Digital Sky Survey (SDSS). The quasar sample spans a redshift range of 0.044 less than or equal to z less than or equal to 4.789 and an absolute r' magnitude range of -18.0 to -26.5. The input spectra cover an observed wavelength range of 3800-9200 Angstrom at a resolution of 1800. The median composite covers a rest-wavelength range from 800 to 8555 Angstrom and reaches a peak signal-to-noise ratio of over 300 per 1 Angstrom resolution element in the rest frame. We have identified over 80 emission-line features in the spectrum. Emission-line shifts relative to nominal laboratory wavelengths are seen for many of the ionic species. Peak shifts of the broad permitted and semiforbidden lines are strongly correlated with ionization energy, as previously suggested, but we find that the narrow forbidden lines are also shifted by amounts that are strongly correlated with ionization energy. The magnitude of the forbidden line shifts is less than or similar to 100 km s(-1), compared with shifts of up to 550 km s(-1) for some of the permitted and semiforbidden lines. At wavelengths longer than the Ly alpha emission, the continuum of the geometric mean composite is well fitted by two power laws, with a break at approximate to 5000 Angstrom. The frequency power-law index, alpha (v), is -0.44 from approximate to 1300 to 5000 and -2.45 redward of approximate to 5000 The abrupt change in slope can be accounted for partly by host-galaxy contamination at low redshift. Stellar absorption lines, including higher order Balmer lines, seen in the composites suggest that young or intermediate-age stars make a significant contribution to the light of the host galaxies. Most of the spectrum is populated by blended emission lines, especially in the range 1500-3500 Angstrom, which can make the estimation of quasar continua highly uncertain unless large ranges in wavelength are observed. An electronic table of the median quasar template is available.
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    Optical and radio properties of extragalactic sources observed by the first survey and the Sloan Digital Sky Survey
    (2002) Ivezic, Z; Menou, K; Knapp, GR; Strauss, MA; Lupton, RH; Vanden Berk, DE; Richards, GT; Tremonti, C; Weinstein, MA; Anderson, S; Bahcall, NA; Becker, RH; Bernardi, M; Blanton, M; Eisenstein, D; Fan, XH; Finkbeiner, D; Finlator, K; Frieman, J; Gunn, JE; Hall, PB; Kim, RSJ; Kinkhabwala, A; Narayanan, VK; Rockosi, CM; Schlegel, D; Schneider, DP; Strateva, I; SubbaRao, M; Thakar, AR; Voges, W; White, RL; Yanny, B; Brinkmann, J; Doi, M; Fukugita, M; Hennessy, GS; Munn, JA; Nichol, RC; York, DG
    We discuss the optical and radio properties of similar to30,000 FIRST (radio, 20 cm, sensitive to 1 mJy) sources positionally associated within 1."5 with a Sloan Digital Sky Survey (SDSS) (optical, sensitive to r*similar to22.2) source in 1230 deg(2) of sky. The matched sample represents similar to30% of the 108,000 FIRST sources and 0.1% of the 2.5x10(7) SDSS sources in the studied region. SDSS spectra are available for 4300 galaxies and 1154 quasars from the matched sample and for a control sample of 140,000 galaxies and 20, 000 quasars in 1030 deg(2) of sky. Here we analyze only core sources, which dominate the sample; the fraction of SDSS-FIRST sources with complex radio morphology is determined to be less than 10%. This large and unbiased catalog of optical identifications provides much firmer statistical footing for existing results and allows several new findings. The majority (83%) of the FIRST sources identified with an SDSS source brighter than r*=21 are optically resolved; the fraction of resolved objects among the matched sources is a function of the radio flux, increasing from similar to50% at the bright end to similar to90% at the FIRST faint limit. Nearly all optically unresolved radio sources have nonstellar colors indicative of quasars. We estimate an upper limit of similar to5% for the fraction of quasars with broadband optical colors indistinguishable from those of stars. The distribution of quasars in the radio flux optical flux plane suggests the existence of the "quasar radio dichotomy" 8%+/-1% of all quasars with i*<18.5 are radio-loud, and this fraction seems independent of redshift and optical luminosity. The radio-loud quasars have a redder median color by 0.08±0.02 mag, and show a 3 times larger fraction of objects with extremely red colors. FIRST galaxies represent 5% of all SDSS galaxies with r*<17.5, and 1% for r*<20, and are dominated by red (u*-r*>2.22) galaxies, especially those with r*>17.5. Magnitude- and redshift-limited samples show that radio galaxies have a different optical luminosity distribution than nonradio galaxies selected by the same criteria; when galaxies are further separated by their colors, this result remains valid for both blue and red galaxies. For a given optical luminosity and redshift, the observed optical colors of radio galaxies are indistinguishable from those of all SDSS galaxies selected by identical criteria. The distributions of radio-to-optical flux ratio are similar for blue and red galaxies in redshift-limited samples; this similarity implies that the difference in their luminosity functions and resulting selection effects are the dominant cause for the preponderance of red radio galaxies in flux-limited samples. The fraction of radio galaxies whose emission-line ratios indicate an AGN(30%), rather than starburst, origin is 6 times larger than the corresponding fraction for all SDSS galaxies (r*<17.5). We confirm that the AGN-to-starburst galaxy number ratio increases with radio flux and find that radio emission from AGNs is more concentrated than radio emission from starburst galaxies.
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    Photometric redshifts from reconstructed quasar templates
    (2001) Budavári, T; Csabai, I; Szalay, AS; Connolly, AJ; Szokoly, GP; Vanden Berk, DE; Richards, GT; Weinstein, MA; Schneider, DP; Benítez, N; Brinkman, J; Brunner, R; Hall, PB; Hennessy, GS; Ivezic, Z; Kunszt, PZ; Munn, JA; Nichol, RC; Pier, JR; York, DG
    From Sloan Digital Sky Survey (SDSS) commissioning photometric and spectroscopic data, we investigate the utility of photometric redshift techniques in the task of estimating QSO redshifts. We consider empirical methods (e.g., nearest neighbor searches and polynomial fitting), standard spectral template fitting, and hybrid approaches (i.e., training spectral templates from spectroscopic and photometric observations of QSOs). We find that in all cases, because of the presence of strong emission lines within the QSO spectra, the nearest neighbor and template-fitting methods are superior to the polynomial-fitting approach. Applying a novel reconstruction technique, we can, from the SDSS multicolor photometry, reconstruct a statistical representation of the underlying SEDs of the SDSS QSOs. Although the reconstructed templates are based on only broadband photometry, the common emission lines present within the QSO spectra can be recovered in the resulting spectral energy distributions. The technique should be useful in searching for spectral differences among QSOs at a given redshift, in searching for spectral evolution of QSOs, in comparing photometric redshifts for objects beyond the SDSS spectroscopic sample with those in the well-calibrated photometric redshifts for objects brighter than 20th magnitude, and in searching for systematic and time-variable effects in the SDSS broadband photometric and spectral photometric calibrations.
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    Photometric redshifts of quasars
    (2001) Richards, GT; Weinstein, MA; Schneider, DP; Fan, XH; Strauss, MA; Vanden Berk, DE; Annis, J; Burles, S; Laubacher, EM; York, DG; Frieman, JA; Johnston, D; Scranton, R; Gunn, JE; Nichol, RC; Ivezic, Z; Nichol, RC; Budavári, T; Csabai, I; Szalay, AS; Connolly, AJ; Szokoly, GP; Bahcall, NA; Benítez, N; Brinkmann, J; Brunner, R; Fukugita, M; Hall, PB; Hennessy, GS; Knapp, GR; Kunszt, PZ; Lamb, DQ; Munn, JA; Newberg, HJ; Stoughton, C
    We demonstrate that the design of the Sloan Digital Sky Survey (SDSS) filter system and the quality of the SDSS imaging data are sufficient for determining accurate and precise photometric redshifts of quasars. Using a sample of 2625 quasars, we show that "photo-z" determination is even possible for z less than or equal to2.2 despite the lack of a strong continuum break, which robust photo-z techniques normally require. We find that, using our empirical method on our sample of objects known to be quasars, approximately 70% of the photometric redshifts are correct to within Deltaz = 0.2; the fraction of correct photometric redshifts is even better for z >3. The accuracy of quasar photometric redshifts does not appear to be dependent upon magnitude to nearly 21st magnitude in i'. Careful calibration of the color-redshift relation to 21st magnitude may allow for the discovery of similar to 10(6) quasar candidates in addition to the 10(5) quasars that the SDSS will confirm spectroscopically. We discuss the efficient selection of quasar candidates from imaging data for use with the photometric redshift technique and the potential scientific uses of a large sample of quasar candidates with photometric redshifts.
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    Sloan Digital Sky Survey
    (2002) Stoughton, C; Lupton, RH; Bernardi, M; Blanton, MR; Burles, S; Castander, FJ; Connolly, AJ; Eisenstein, DJ; Frieman, JA; Hennessy, GS; Hindsley, RB; Ivezic, Z; Kent, S; Kunszt, PZ; Lee, BC; Meiksin, A; Munn, JA; Newberg, HJ; Nichol, RC; Nicinski, T; Pier, JR; Richards, GT; Richmond, MW; Schlegel, DJ; Smith, JA; Strauss, MA; SubbaRao, M; Szalay, AS; Thakar, AR; Tucker, DL; Vanden Berk, DE; Yanny, B; Adelman, JK; Anderson, JE; Anderson, SF; Annis, J; Bahcall, NA; Bakken, JA; Bartelmann, M; Bastian, S; Bauer, A; Berman, E; Böhringer, H; Boroski, WN; Bracker, S; Briegel, C; Briggs, JW; Brinkmann, J; Brunner, R; Carey, L; Carr, MA; Chen, B; Christian, D; Colestock, PL; Crocker, JH; Csabai, IN; Czarapata, PC; Dalcanton, J; Davidsen, AF; Davis, JE; Dehnen, W; Dodelson, S; Doi, M; Dombeck, T; Donahue, M; Ellman, N; Elms, BR; Evans, ML; Eyer, L; Fan, XH; Federwitz, GR; Friedman, S; Fukugita, M; Gal, R; Gillespie, B; Glazebrook, K; Gray, J; Grebel, EK; Greenawalt, B; Greene, G; Gunn, JE; de Haas, E; Haiman, Z; Haldeman, M; Hall, PB; Hamabe, M; Hansen, B; Harris, FH; Harris, H; Harvanek, M; Hawley, SL; Hayes, JJE; Heckman, TM; Helmi, A; Henden, A; Hogan, CJ; Hogg, DW; Holmgren, DJ; Holtzman, J; Huang, CH; Hull, C; Ichikawa, SI; Ichikawa, T; Johnston, DE; Kauffmann, G; Kim, RSJ; Kimball, T; Kinney, E; Klaene, M; Kleinman, SJ; Klypin, A; Knapp, GR; Korienek, J; Krolik, J; Kron, RG; Krzesinski, J; Lamb, DQ; Leger, RF; Limmongkol, S; Lindenmeyer, C; Long, DC; Loomis, C; Loveday, J; MacKinnon, B; Mannery, EJ; Mantsch, PM; Margon, B; McG'hee, P; Mckay, TA; McLean, B; Menou, K; Merelli, A; Mo, HJ; Monet, DG; Nakamura, O; Narayanan, VK; Nash, T; Neilsen, EH; Newman, PR; Nitta, A; Odenkirchen, M; Okada, N; Okamura, S; Ostriker, JP; Owen, R; Pauls, AG; Peoples, J; Peterson, RS; Petravick, D; Pope, A; Pordes, R; Postman, M; Prosapio, A; Quinn, TR; Rechenmacher, R; Rivetta, CH; Rix, HW; Rockosi, CM; Rosner, R; Ruthmansdorfer, K; Sandford, D; Schneider, DP; Scranton, R; Sekiguchi, M; Sergey, G; Sheth, R; Shimasaku, K; Smee, S; Snedden, SA; Stebbins, A; Stubbs, C; Szapudi, I; Szkody, P; Szokoly, GP; Tabachnik, S; Tsvetanov, Z; Uomoto, A; Vogeley, MS; Voges, W; Waddell, P; Walterbos, R; Wang, SI; Watanabe, M; Weinberg, DH; White, RL; White, SDM; Wilhite, B; Wolfe, D; Yasuda, N; York, DG; Zehavi, I; Zheng, W
    The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere and collect spectra of 10 6 galaxies, 100,000 quasars, 30,000 stars, and 30,000 serendipity targets. In 2001 June, the SDSS released to the general astronomical community its early data release, roughly 462 deg(2) of imaging data including almost 14 million detected objects and 54,008 follow-up spectra. The imaging data were collected in drift-scan mode in five bandpasses (u, g, r, i, and z); our 95% completeness limits for stars are 22.0, 22.2, 22.2, 21.3, and 20.5, respectively. The photometric calibration is reproducible to 5%, 3%, 3%, 3%, and 5%, respectively. The spectra are flux- and wavelength-calibrated, with 4096 pixels from 3800 to 9200 Angstrom at R approximate to 1800. We present the means by which these data are distributed to the astronomical community, descriptions of the hardware used to obtain the data, the software used for processing the data, the measured quantities for each observed object, and an overview of the properties of this data set.
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    The first data release of the Sloan Digital Sky Survey
    (2003) Abazajian, K; Adelman-McCarthy, JK; Agüeros, MA; Allam, SS; Anderson, SF; Annis, J; Bahcall, NA; Baldry, IK; Bastian, S; Berlind, A; Bernardi, M; Blanton, MR; Blythe, N; Bochanski, JJ; Boroski, WN; Brewington, H; Briggs, JW; Brinkmann, J; Brunner, RJ; Budavári, T; Carey, LN; Carr, MA; Castander, FJ; Chiu, K; Collinge, MJ; Connolly, AJ; Covey, KR; Csabai, I; Dalcanton, JJ; Dodelson, S; Doi, M; Dong, F; Eisenstein, DJ; Evans, ML; Fan, XH; Feldman, PD; Finkbeiner, DP; Friedman, SD; Frieman, JA; Fukugita, M; Gal, RR; Gillespie, B; Glazebrook, K; Gonzalez, CF; Gray, J; Grebel, EK; Grodnicki, L; Gunn, JE; Gurbani, VK; Hall, PB; Hao, L; Harbeck, D; Harris, FH; Harris, HC; Harvanek, M; Hawley, SL; Heckman, TM; Helmboldt, JF; Hendry, JS; Hennessy, GS; Hindsley, RB; Hogg, DW; Holmgren, DJ; Holtzman, JA; Homer, L; Hui, L; Ichikawa, SI; Ichikawa, T; Inkmann, JP; Ivezic, Z; Jester, S; Johnston, DE; Jordan, B; Jordan, WP; Jorgensen, AM; Juric, M; Kauffmann, G; Kent, SM; Kleinman, SJ; Knapp, GR; Kniazev, AY; Kron, RG; Krzesinski, J; Kunszt, PZ; Kuropatkin, N; Lamb, DQ; Lampeitl, H; Laubscher, BE; Lee, BC; Leger, RF; Li, N; Lidz, A; Lin, H; Loh, YS; Long, DC; Loveday, J; Lupton, RH; Malik, T; Margon, B; McGehee, PM; McKay, TA; Meiksin, A; Miknaitis, GA; Moorthy, BK; Munn, JA; Murphy, T; Nakajima, R; Narayanan, VK; Nash, T; Neilsen, EH; Newberg, HJ; Newman, PR; Nichol, RC; Nicinski, T; Nieto-Santisteban, M; Nitta, A; Odenkirchen, M; Okamura, S; Ostriker, JP; Owen, R; Padmanabhan, N; Peoples, J; Pier, JR; Pindor, B; Pope, AC; Quinn, TR; Rafikov, RR; Raymond, SN; Richards, GT; Richmond, MW; Rix, HW; Rockosi, CM; Schaye, J; Schlegel, DJ; Schneider, DP; Schroeder, J; Scranton, R; Sekiguchi, M; Seljak, U; Sergey, G; Sesar, B; Sheldon, E; Shimasaku, K; Siegmund, WA; Silvestri, NM; Sinisgalli, AJ; Sirko, E; Smith, JA; Smolcic, V; Snedden, SA; Stebbins, A; Steinhardt, C; Stinson, G; Stoughton, C; Strateva, IV; Strauss, MA; Subbarao, M; Szalay, AS; Szapudi, I; Szkody, P; Tasca, L; Tegmark, M; Thakar, AR; Tremonti, C; Tucker, DL; Uomoto, A; Vanden Berk, DE; Vandenberg, J; Vogeley, MS; Voges, W; Vogt, NP; Walkowicz, LM; Weinberg, DH; West, AA; White, SDM; Wilhite, BC; Willman, B; Xu, YZ; Yanny, B; Yarger, J; Yasuda, N; Yip, CW; Yocum, DR; York, DG; Zakamska, NL; Zehavi, I; Zheng, W; Zibetti, S; Zucker, DB
    The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its First Data Release. This consists of 2099 deg(2) of five-band (u, g, r, i, z) imaging data, 186,240 spectra of galaxies, quasars, stars and calibrating blank sky patches selected over 1360 deg(2) of this area, and tables of measured parameters from these data. The imaging data go to a depth of r approximate to 22.6 and are photometrically and astrometrically calibrated to 2% rms and 100 mas rms per coordinate, respectively. The spectra cover the range 3800-9200 Angstrom, with a resolution of 1800-2100. This paper describes the characteristics of the data with emphasis on improvements since the release of commissioning data (the SDSS Early Data Release) and serves as a pointer to extensive published and on-line documentation of the survey.
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    The Sloan Digital Sky Survey Quasar Catalog. I. Early data release
    (2002) Schneider, DP; Richards, GT; Fan, XH; Hall, PB; Strauss, MA; Vanden Berk, DE; Gunn, JE; Newberg, HJ; Reichard, TA; Stoughton, C; Voges, W; Yanny, B; Anderson, SF; Annis, J; Bahcall, NA; Bauer, A; Bernardi, M; Blanton, MR; Boroski, WN; Brinkmann, J; Briggs, JW; Brunner, R; Burles, S; Carey, L; Castander, FJ; Connolly, AJ; Csabai, I; Doi, M; Friedman, S; Frieman, JA; Fukugita, M; Heckman, TM; Hennessy, GS; Hindsley, RB; Hogg, DW; Ivezic, Z; Kent, S; Knapp, GR; Kunzst, PZ; Lamb, DQ; Leger, RF; Long, DC; Loveday, J; Lupton, RH; Margon, B; Meiksin, A; Merelli, A; Munn, JA; Newcomb, M; Nichol, RC; Owen, R; Pier, JR; Pope, A; Rockosi, CM; Saxe, DH; Schlegel, D; Siegmund, WA; Smee, S; Snir, Y; SubbaRao, M; Szalay, AS; Thakar, AR; Uomoto, A; Waddell, P; York, DG
    We present the first edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists of the 3814 objects ( 3000 discovered by the SDSS) in the initial SDSS public data release that have at least one emission line with a full width at half-maximum larger than 1000 km s(-1), luminosities brighter than M(i*) = -23, and highly reliable redshifts. The area covered by the catalog is 494 deg(2); the majority of the objects were found in SDSS commissioning data using a multicolor selection technique. The quasar redshifts range from 0.15 to 5.03. For each object the catalog presents positions accurate to better than 0".2 rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.05 mag, radio and X-ray emission properties, and information on the morphology and selection method. Calibrated spectra of all objects in the catalog, covering the wavelength region 3800-9200 Angstrom at a spectral resolution of 1800-2100, are also available. Since the quasars were selected during the commissioning period, a time when the quasar selection algorithm was undergoing frequent revisions, the sample is not homogeneous and is not intended for statistical analysis.
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    The Sloan Digital Sky Survey Quasar Catalog. II. First data release
    (2003) Schneider, DP; Fan, XH; Hall, PB; Jester, S; Richards, GT; Stoughton, C; Strauss, MA; SubbaRao, M; Vanden Berk, DE; Anderson, SF; Brandt, WN; Gunn, JE; Gray, J; Trump, JR; Voges, W; Yanny, B; Bahcall, NA; Blanton, MR; Boroski, WN; Brinkmann, J; Brunner, R; Burles, S; Castander, FJ; Doi, M; Eisenstein, D; Frieman, JA; Fukugita, M; Heckman, TM; Hennessy, GS; Ivezic, Z; Kent, S; Knapp, GR; Lamb, DQ; Lee, BC; Loveday, J; Lupton, RH; Margon, B; Meiksin, A; Munn, JA; Newberg, HJ; Nichol, RC; Niederste-Ostholt, M; Pier, JR; Richmond, MW; Rockosi, CM; Saxe, DH; Schlegel, DJ; Szalay, AS; Thakar, AR; Uomoto, A; York, DG
    We present the second edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists of the 16,713 objects in the SDSS First Data Release that have luminosities larger than M-i=-22 (in a cosmology with H-0=70 km s(-1) Mpc(-1), Omega(M)=0.3, and Omega(Lambda)=0.7), have at least one emission line with FWHM larger than 1000 km s(-1), and have highly reliable redshifts. The area covered by the catalog is approximate to1360 deg(2). The quasar redshifts range from 0.08 to 5.41, with a median value of 1.43. For each object, the catalog presents positions accurate to better than 0."2 rms per coordinate, five- band (ugriz) CCD-based photometry with typical accuracy of 0.03 mag, and information on the morphology and selection method. The catalog also contains some radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. Calibrated digital spectra of all objects in the catalog, covering the wavelength region 3800-9200 Angstrom at a spectral resolution of 1800-2100, are available. This publication supersedes the first SDSS Quasar Catalog, which was based on material from the SDSS Early Data Release. A summary of corrections to current quasar databases is also provided. The majority of the objects were found in SDSS commissioning data using a multicolor selection technique. Since the quasar selection algorithm was undergoing testing during the entire observational period covered by this catalog, care must be taken when assembling samples from the catalog for use in statistical studies. A total of 15,786 objects (94%) in the catalog were discovered by the SDSS; 12,173 of the SDSS discoveries are reported here for the first time. Included in the new discoveries are five quasars brighter than i=16.0 and 17 quasars with redshifts larger than 4.5.