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SDSS Data Release 6
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>SDSS Data Release 6</title> <link rel="stylesheet" type="text/css" href="./includes/sdss.css"> </head> <body topmargin="0" leftmargin="0" marginheight="0" marginwidth="0"> <table cellpadding="0" cellspacing="0" border="0" bgcolor="#ffffff"><tr> <td colspan="5" bgcolor="#6352c7" ><img alt="" src="images/hpHdrRel6.gif" width="760" height="104" border="0"></td> <td width="5" class="colorborder"><img src="./images/spacer.gif" width="5" height="1" border="0" alt=""></td> </tr><tr> <td width="132" bgcolor="#000000" valign="top"> <!--Begin menubar for entry page (no link to "home"; from leftside-top.php)--> <table cellpadding="0" cellspacing="0" border="0" width="132"><tr> <td class="linkcell"><a href="./start/index.php" class="none"><span class="link">Where to Start</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./start/aboutdr6.php" class="none"><span class="link">About DR6</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./news/index.php" class="none"><span class="link">News and Updates</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./tutorials/index.php" class="none"><span class="link">Tutorials</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./products/index.php" class="none"><span class="link">Data Products</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./access/index.php" class="none"><span class="link">Data Access</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./coverage/index.php" class="none"><span class="link">Sky Coverage</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./instruments/index.php" class="none"><span class="link">Instruments</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./dataflow/index.php" class="none"><span class="link">Data Flow</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./algorithms/index.php" class="none"><span class="link">Algorithms</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./glossary/index.php" class="none"><span class="link">Glossary</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./help/known.php" class="none"><span class="link">Known Problems</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./help/index.php" class="none"><span class="link">Help and Feedback</span></a></td> </tr><tr> <td class="divider"><img alt="" src="./images/spacer.gif" width="1" height="1" border="0"></td> </tr><tr> <td class="linkcell"><a href="./search/index.php" class="none"><span class="link">Search</span></a></td> </tr><tr> <td><img alt="" src="./images/menuBottom.gif" width="132" height="6" border="0"></td> </tr><tr> <td><img alt="" src="./images/fields.gif" width="132" height="103" border="0"></td> </tr> </table> <!--End menu bar--> </td> <td width="5" class="colorborder"><img alt="" src="images/spacer.gif" width="5" height="1" border="0"></td> <td valign="top"> <table cellpadding="8" cellspacing="0" border="0"><tr> <td class="body"> <p>The Sloan Digital Sky Survey (see <a href="http://www.sdss.org">www.sdss.org</a> for general information) will map one-quarter of the entire sky and perform a redshift survey of galaxies, quasars and stars. The DR6 is the sixth major data release and provides <a href="./products/index.php">images, imaging catalogs, spectra, and redshifts</a> for download. It is the first data release of SDSS-II, an extension of the original SDSS consisting of three subprojects: Legacy, <a href="./start/aboutsegue.php">SEGUE</a> and a Supernova survey. The final data release from the Supernova Survey is available at <a href="../../drsn/DRSN_data_release.php">www.sdss.org/drsn/DRSN_data_release.php</a></p> <p><a href="./start/aboutdr6.php">About DR6</a> explains what is new in DR6, and lists remaining or new caveats and subtleties in the data.</p> <p>Please refer to the <a href="./coverage/credits.php">credits page</a> for our sources of funding, participating institutions, and how to acknowledge the use of SDSS data in your publications. Please also note how to refer to SDSS sources in your publications using the proper <a href="./coverage/IAU.php">IAU nomenclature for SDSS sources</a>.</p> <h2>Imaging</h2> <table border="1" width="100%"> <tr> <td>Footprint area</td> <td> <table border="1"> <tr> <td>Total cataloged in CAS</td><td>9583 sq. deg.</td> </tr> <tr> <td>Legacy</td><td>8417 sq. deg.</td> </tr><tr> <td>SEGUE</td><td>1592 sq. deg. of images in DAS<br />1166 sq. deg. of catalogs in CAS</td> </tr><tr> <td><a href="../../drsn/DRSN_data_release.php">Supernova Survey</a></td><td>~300 sq. deg., repeated >40 times</td> </tr><tr> <td><a href="./start/aboutdrsup.php">M31 / Perseus scan</a></td><td>26 sq. deg.</td> </tr><tr> <td><a href="http://photo.astro.princeton.edu/oriondatarelease/">Low galactic latitude fields ("Orion" runs)</a></td> <td>832 sq. deg.</td> </tr> </table> </td> </tr><tr> <td>Imaging catalog</td> <td>287 million unique objects (SEGUE: 57 million, Legacy: 230 million)</td> </tr><tr> <td>Data volume</td> <td> <table border="1"> <tr> <td>images</td><td>10.0 TB</td> </tr><tr> <td>catalogs (<a href="./access/index.php#DAS">DAS</a>, fits format)</td><td>2 TB</td> </tr><tr> <td>catalogs (<a href="./access/index.php#CAS">CAS</a>, SQL database)</td><td>4 TB</td> </tr> </table> </td> </tr><tr> <td>Average wavelengths and magnitude limits <br /> (95% detection repeatability for point sources)</td> <td> <table border="1"> <tr> <td><var>u</var></td> <td><var>g</var></td> <td><var>r</var></td> <td><var>i</var></td> <td><var>z</var></td> </tr> <tr> <td>3551Å</td> <td>4686Å</td> <td>6165Å</td> <td>7481Å</td> <td>8931Å</td> </tr> <tr> <td>22.0</td> <td>22.2</td> <td>22.2</td> <td>21.3</td> <td>20.5</td> </tr> </table> </td> </tr><tr> <td>PSF width</td> <td>1.4" median in <var>r</var></td> </tr><tr> <td>Pixel size</td> <td>0.396"</td> </tr><tr> <td>Exposure time for each pixel</td> <td>53.9 s</td> </tr><tr> <td>Photometric calibration</td> <td> <table> <tr> <td> <table border="1"> <caption>Regular CAS and DAS</caption> <tr> <td><var>r</var></td> <td><var>u-g</var></td> <td><var>g-r</var></td> <td><var>r-i</var></td> <td><var>i-z</var></td> </tr><tr> <td>2%</td> <td>3%</td> <td>2%</td> <td>2%</td> <td>3%</td> </tr> </table> </td> <td> <table border="1"> <caption>Only Ubercal table in CAS</caption> <tr> <td><var>r</var></td> <td><var>u-g</var></td> <td><var>g-r</var></td> <td><var>r-i</var></td> <td><var>i-z</var></td> </tr><tr> <td>1%</td> <td>2.2%</td> <td>1.5%</td> <td>1.5%</td> <td>1.5%</td> </tr> </table> </td> </tr> </table> </td> </tr><tr> <td>Astrometry</td> <td>< 0.1" rms absolute per coordinate</td> </tr> </table> <h2>Spectroscopy</h2> <table border="1" width="100%"> <tr> <td>Spectroscopic area</td> <td> <table border="1"> <tr><td>Total</td> <td>7425 sq. deg.</td> </tr><tr> <td>Legacy</td> <td>6860 sq. deg.</td> </tr><tr> <td>SEGUE</td> <td>565 sq. deg.</td> </tr> </table> </td> </tr><tr> <td>Wavelength coverage</td> <td>3800-9200Å</td> </tr><tr> <td>Resolution</td> <td>1800-2200</td> </tr><tr> <td>Signal-to-noise</td> <td>>4 per pixel at <var>g</var>=20.2</td> </tr><tr> <td>Redshift accuracy</td> <td>30 km/sec rms for main galaxy sample (from repeat observations)</td> </tr><tr> <td>Target magnitude limits for main samples</td> <td>Galaxies: Petrosian <var>r</var> <17.77<br /> Quasars: PSF <var>i</var> <19.1 (20.2 for objects likely at z>2.3)</td> </tr><tr> <td>Spectroscopic catalog</td> <td> <table border="1"> <colgroup> <col> <col span="3" align="right"> </colgroup> <tr> <th>Class</th> <th align="center">N(total)</th> <th align="center">N(main)</th> <th align="center">N(SEGUE)</th> </tr><tr> <td>All</td> <td>1,271,680</td> <td>1,163,520</td> <td>108,160</td> </tr><tr> <td>Galaxies</td> <td>790,860</td> <td>790,220</td> <td>640</td> </tr><tr> <td>Quasars (z <2.3)</td> <td>90,108</td> <td>89,458</td> <td>650</td> </tr><tr> <td>Quasars (z ≥2.3)</td> <td>13,539</td> <td>12,892</td> <td>647</td> </tr><tr> <td>M stars and later</td> <td>69,052</td> <td>64,895</td> <td>4,157</td> </tr><tr> <td>Other stars</td> <td>218,019</td> <td>126,351</td> <td>91,668</td> </tr><tr> <td>Sky spectra</td> <td>68,770</td> <td>59,843</td> <td>8,927</td> </tr><tr> <td>Unknown</td> <td>21,332</td> <td>19,861</td> <td>1,471</td> </tr> </table> 640 spectra are observed simultaneously on one <em>plate</em>. There are: <ul> <li>1520 Legacy ("main-survey") plates,<li> <li>64 repeat observations ("extra plates") of 55 distinct Legacy plates,</li> <li>234 observations of 226 distinct <a href="./products/spectra/special.php#nonSEGUE">special plates</a>, and</li> <li> 169 observations of 162 distinct <a href="./products/spectra/special.php#SEGUE">special plates taken under SEGUE</a>. </li> </ul> </td> </tr><tr> <td>Data volume</td> <td> <table border="1"> <tr> <td>calibrated spectra ("2d")</td><td>80 GB</td> </tr><tr> <td>spectra, redshifts, line measurements ("1d")</td><td>230 GB</td> </tr> </table> </td> </tr> </table> <h2>Previous data releases</h2> <p>For reference, we provide links to earlier data releases. The current data release always provides both the largest sky coverage and the highest-quality data and reductions.</p> <ul> <li><a href="http://www.sdss.org/dr1/">Data Release 1 (DR1)</a></li> <li><a href="http://www.sdss.org/dr2/">Data Release 2 (DR2)</a></li> <li><a href="http://www.sdss.org/dr3/">Data Release 3 (DR3)</a></li> <li><a href="http://www.sdss.org/dr4/">Data Release 4 (DR4)</a></li> <li><a href="http://www.sdss.org/dr5/">Data Release 5 (DR5)</a></li> </ul> <hr> <address> <!-- Warning the parse_this is used in bin/webPublish.sh --> This is version <!-- parse_this --> v6_20081024_0621 . <!-- Done with reporting the version. --> This page was last modified on $Date: 2008/06/11 19:48:56 $ (UT). <!-- Created: Tue Jul 30 21:49:21 DST 2002 --> <p>If you are using Netscape 4.x and see oversized fonts, please look at the <a href="./coverage/credits.php#website">workaround on the Credits page</a>.</p></address> </td> </tr> </table> <img alt="" src="./images/spacer.gif" width="314" height="1" border="0"></td> <td width="304" valign="top" align="center" bgcolor="#dddddd"> <table cellpadding="8" cellspacing="0" border="0" width="132"> <tr> <td class="newsBox"><strong>News</strong> <p> <a href="./news/index.php">BUG</a> in spectroscopic synthetic magnitudes: mag_0,mag_1, mag_2 (they are u,g,r not g,r,i) in DR6 CAS and in spSpec DAS headers <p> The DR6 paper (<a href="https://ui.adsabs.harvard.edu/abs/2008ApJS..175..297A">Adelman-McCarthy, J.K. et al. 2008, ApJS, 175, 297-313</a>) has appeared in print.</p> <!-- <a href="./news/index.php">More details...</a> --> </td> </tr> <tr> <td><a href="./dr6photo_big.gif"> <img src="./dr6photo.gif" alt="Imaging Sky Image" border="0"> </a> <table cellpadding="2" cellspacing="0" border="0" width="272"><tr> <td class="infoBoxes">SDSS DR6 Imaging Sky Coverage (Aitoff projection of Equatorial coordinates)</td> </tr></table> <br> <a href="./dr6spectro_big.gif"> <img src="./dr6spectro.gif" alt="Spectral Sky Image" border="0"> </a> <table cellpadding="2" cellspacing="0" border="0" width="272"><tr> <td class="infoBoxes">SDSS DR6 Spectral Sky Coverage (Aitoff projection of Equatorial coordinates)</td> </tr></table> <br> <a href="./seguephoto_big.gif"> <img src="./seguephoto.gif" alt="Imaging Sky Image" border="0"> </a> <table cellpadding="2" cellspacing="0" border="0" width="272"><tr> <td class="infoBoxes">SEGUE DR6 Imaging Sky Coverage (Aitoff projection of Equatorial coordinates)</td> </tr></table> <br> <a href="./seguespectro_big.gif"> <img src="./seguespectro.gif" alt="Spectral Sky Image" border="0"> </a> <table cellpadding="2" cellspacing="0" border="0" width="272"><tr> <td class="infoBoxes">SEGUE DR6 Spectral Sky Coverage (Aitoff projection of Equatorial coordinates)</td> </tr></table></td> </tr></table> <img alt="" src="./images/spacer.gif" width="304" height="1" border="0"></td> <td width="5" class="colorborder"><img alt="" src="./images/spacer.gif" width="5" height="1" border="0"></td> </tr><tr> <td class="footer"> </td> <td width="5" class="colorborder"><img alt="" src="./images/spacer.gif" width="5" height="1" border="0"></td> <td colspan="2" class="footer"> Submit your questions to <a href="http://www.lib.uchicago.edu/e/crerar/using/sloan.html"> the SDSS helpdesk</a> </td> <td width="5" class="colorborder"><img alt="" src="./images/spacer.gif" width="5" height="1" border="0"></td> </tr></table> </body> </html>