Astrofísica - Universidad Complutense de Madrid

NOT-ALFOSC Observations - 14 June 2005

Information in this page:

Filters set-up and focus      Observational sequence      Objects catalogs      Objects visibility      Additional information

Filters set-up and focus

Every galaxy has to be observed in two filters:
  1. BROAD BAND filter: r' SDSS set, NOT #110. Every galaxy needs a 900 s exposure by using this filter.
  2. Hα NARROW BAND filter: 2700 s exposure. The narrow band filter to be used depends on the redshift of the galaxy.

We need our images to be focused, so you will have to focus after the flat fields. Focus offsets for the three filters above are:

Filter Focus offset
r' SDSS set +95
(NOT web page information)
Hα #17+110
(May 2005 measurement)
Hα #31+110
(May 2005 measurement)

Note that the telescope focus changes with the temperature (and the NOT telescope automatically update the focus). So you just have to focus at the beginning of the night and change by applying a different offset for each filter you will use.

Observational sequence

Here is a table with (hopefully) the observational sequence of the whole night. Galaxy coordinates J2000 are in the file NOT_jun_coords.dat and below, section Objects catalogs. Also see the section Objects visibility for a plot of objects altitude vs UT.

I am taking into account overheads due to pointing and data acquisition, if you see that it is going to be longer and you can end your observations before 01:25 UT I will be very grateful.

UT Object Filter Exposition time Comments
20:18   Sunset
~20:30 - 21:40   Time for flat fields and focus ~ 45 min for FF in last May
~21:40 - 22:45UCM1255+2734 Hα #17
r' #110		 2700 s
900 s 		Twilight at 21:44 UT
~22:45 - 01:25   Time for your observation
~01:25 - 02:35UCM1452+2754 Hα #31
r' #110		 2700 s
900 s
~02:35 - 03:45UCM1659+2928 Hα #31
r' #110		 2700 s
900 s
~03:45 - 04:55UCM2351+2321 Hα #17
r' #110		 2700 s
900 s 		Top priority
Twilight at 04:39 UT
~05:00 - 06:00   Time for flat fields

Objects catalogs

Just the names and coordinates J2000 for the galaxies to be observed: NOT_jun_coords.dat

Here is a table showing the galaxies we would like to observe (they are ordered by increasing RA). Double click in the names to visit a web page compiling some information about the galaxy (including finding charts). There are two galaxies for each hourly interval along the night; column labeled 'Priority' tells you the preferred object. The redshift for every galaxy determines the Hα filter to be used.

See Objects visibility for a plot of the objects altitude along the night.

Name RA (J2000) Dec (J2000) r mag Hα filter Exposition time Priority Comments
UCM1254+2802 12 57 04.6+27 46 2615.76#17Hα: 1 x 2700 s
r': 1 x 900 s		2
UCM1255+2734 12 58 18.5+27 18 4115.99#17Hα: 1 x 2700 s
r': 1 x 900 s		1
UCM1431+2702 14 33 45.1+26 49 1616.41#31Hα: 1 x 2700 s
r': 1 x 900 s		2
UCM1452+2754 14 54 22.5+27 42 0515.43#31Hα: 1 x 2700 s
r': 1 x 900 s		1
UCM1557+1423 16 00 08.3+14 15 3015.82#31Hα: 1 x 2700 s
r': 1 x 900 s		2
UCM1653+2644 16 55 09.7+26 39 45-- #31Hα: 1 x 2700 s
r': 1 x 900 s		3
UCM1659+2928 17 01 07.9+29 24 2414.91#31Hα: 1 x 2700 s
r': 1 x 900 s		1
UCM2351+2321 23 53 39.6+23 37 5716.39#17Hα: 1 x 2700 s
r': 1 x 900 s		1Top priority for us
Visible at the end of the night
UCM2321+2149 23 24 08.2+22 06 0915.85#31Hα: 1 x 2700 s
r': 1 x 900 s		2

Objects visibility

The visibility of the selected galaxies (plot at right, double click to enlarge) leads to the observational sequence (see details in that section, including an approximated timetable):

  1. At the beginning of the night (and before your eclipse):

    RA ~ 13h → UCM1255+2734

  2. After your eclipse:

    RA ~ 15-16h → UCM1452+2754 & UCM1659+2928

  3. At the end of the night (beginning before 4:00 UT):

    RA ~ 24h → UCM2321+2149

Galaxies visibility

Objects useful information

You can find more information about the galaxies on our web page: UCM survey web page

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