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ALFALFA

Using SDSS, DSS, and NED

Below, we provide links to the entries for 5 interesting galaxies in several public extragalactic databases: the 7th and 9th release of the Sloan Digital Sky Survey (DR7 is a faster link), the SkyView Digital Sky Survey 1, the Digital Sky Survey 2 Red and Blue, and the NASA Extragalactic Database (NED). Note that the links to DSS1 and DSS2 are provided both at image sizes of 0.03 degrees and 0.1 degrees; for the SDSS image, experiment with the Navigator Tool to learn to zoom in and out, recenter, etc. The NED link provides you with a list of all entries in that database within 10 arcmin around the chosen position. We will discuss more about these images after you look at them!

In all cases, provide the name of the object as you find it in the NED. Then answer the questions asked in each case.

  1. Describe the central regions of this object.
      0849118+601314   132.2992 60.2206   DR7Navigate   DR9Navigate   SkyView.03   SkyView.10   DSS2red.03   DSS2blu.03   DSS2red.10   DSS2blu.10   NED1   NED10

  2. Does the spectrum detected by the SDSS show emission or absorption lines? What is the strongest line?   Hint: Use the SDSS Explore Tool.
      1119144+115707   169.8100 11.9519   DR7Navigate   DR9Navigate   SkyView.03   SkyView.10   DSS2red.03   DSS2blu.03   DSS2red.10   DSS2blu.10   NED1   NED10

  3. What is the redshift of this object? Just for fun, zoom out the SDSS Navigator tool to a scale of 12.676 arcsec/pix. Is there anything interesting to make note of?
      1120169+133513   170.0704 13.5869   DR7Navigate   DR9Navigate   SkyView.03   SkyView.10   DSS2red.03   DSS2blu.03   DSS2red.10   DSS2blu.10   NED1   NED10

  4. Be sure to use the SDSS Navigator tool to zoom out several times (e.g., so the scale is 6.338 arcsec/pix). Describe the surroundings of this object.
      1402113+092623   210.5471 9.4397   DR7Navigate   DR9Navigate   SkyView.03   SkyView.10   DSS2red.03   DSS2blu.03   DSS2red.10   DSS2blu.10   NED1   NED10

  5. What's so odd about this object (as it appears in all the images)? What do you notice when you zoom the SDSS image to a scale of 12.676 arcsec/pix?
      1405014+533944   211.2558 53.6622   DR7Navigate   DR9Navigate   SkyView.03   SkyView.10   DSS2red.03   DSS2blu.03   DSS2red.10   DSS2blu.10   NED1   NED10



Last modified: Thu Nov 7 11:16:57 EST 2013 by becky