README web version of /home/usg/OPS/MTS/readme_xml/readme_79087400

Principal Investigator Email Address

```
usuda@naoj.org
```

Estimated Total Execution Time (hours, including overheads)

```
01:03:54.000
```

General Description

This is an observation to look for the absorption lines of H3+, H2, and
 CO along the line of sight to the Galactic center on the continuum of bright infrared
 sources there.  1) Slit PA and nodding amplitude  in order to make the most of the
 telescope time, we set the slit position angle so that a nearby bright IR source
 is also covered in the same slit, which may also serve as a decent background illumination
 for the absorption line survey. We measured the slit P.A. as accurate as possible
 using our own imaging at Mauna Kea, but, since the slit length of CRIRES is long,
 there is chance that the sources are not precisely in the slit. In such a case,
 we would appreciate if the observers could pay attention to the following possibilities
  - small tweaking of the slit P.A. at the site, so that two source are properly
 centered in the slit, - if this is not possible, we will put the priority to the
 primary source (unambiguously addressed in OBs and finding chart). Please centerd
 the primary source on the slit. In this case, a slight off-centering of the secondary
 source is acceptable.   2) Centering objects on the slit  Beacuse two sources are
 to be covered in one slit, we would like to put the middle of the two sources at
 the center of the slit, instead of putting the primary source at the center of the
 slit. The offsets are shown in the finding chart, and also below.    3) Spectroscopic
 standard
The order of the execution of each OBs is not very cretical, but the calibration
 star HR 6879 is meant to be observed after the object (therefore earlier R.A.).

1) We revise the priority of the objects as follows (the smaller the number, the
 higher the priority). Corresponding calibration stars are give same priority.

   GCS3-2  H3P -> 1
   IRS1W   H3P -> 2
   GCS3-1  H3P -> 3
   GCS3-2  H2  -> 4
   GCS3-2  CO  -> 5
   IRS1W   CO  -> 6
   GCS3-1  CO  -> 7
   IRS16NE H3P -> 8
   IRS16NE CO  -> 9
   All CAL     -> 10

2) If it is possible, we would like to propose a small tweak for a grating setting.

   The primary line we would like to cover by 27/1/i was H2 1-0 S(1) at 2121.8 nm.
 It turns out, by using 27/1/n instead of 27/1/i,
   we can still cover not only the original line of H2, but also another line of
 H3+ as a genuine bonus. The order of the grating stays the
   same (just for a change from "/i" to "/n"). The details of the line positions
 and the margins at both sides of the lines are following.

[27/1/i l_ref = 2123.3 nm]
H2 1-0 S(1) at 2121.8nm/ H3+ tR(6,6) 2093.265nm

Det.1 covers 2093.1 - 2103.3   2093.265     -24km/s to +1437km/s
Det.3 covers 2118.6 - 2128.0   2121.8      -452km/s to  +876km/s


[27/1/n l_ref = 2117.6 nm]
H2 1-0 S(1) at 2121.8nm/ H3+ t(6,6) 2093.265nm

Det.1 covers 2087.0 - 2097.4   2093.265     -897km/s to  +592km/s
Det.3 covers 2112.8 - 2122.4   2121.8      -1272km/s to   +85km/s

3) Vignetting problem
Our configuration lists are as follows for the target lines, wavelength,
detector number, and grating settings:

H3+
  3533.67  R(3,3)l  det3 16/0/n
  3645.09  R(4,4)l  det3 15/-2/n
  3715.48  R(1,1)l  det2 15/-1/i
  2093.265 R(6,6)   det1 27/1/n
H2
  2121.8   1-0 S(1) det3 27/1/n
  2223.5   1-0 S(0) det2 25/-1/n
CO
  2356.12  P(4)     N/A
  2353.87  P(3)     det4 24/-1/i
  2351.67  P(2)     det4 24/-1/i
  2349.50  P(1)     det4 24/-1/i
  2345.31  R(0)     det4 24/-1/n
  2343.27  R(1)     det4 24/-1/n
  2341.28  R(2)     det3 24/-1/i and det 4 24/-1/n
  2339.32  R(3)     det3 24/-1/i
  2337.41  R(4)     det3 24/-1/i
  2335.54  R(5)     det3 24/-1/i
  2333.72  R(6)     det3 24/-1/i and 24/-1/n

Dr. Michael Hilker (ESO) had already confirmed that our settings are fine
because the orders 25 and higher are affected in detector 4.

Waiver Requests

```
No Waiver Request was submitted
```

Critical Observing Condition Constraints

```
none.
```

Time-Critical Aspects

```
none.
```

Special Execution Requirements

... coppied from General Description ...  in order to make the most of
 the telescope time, we set the slit position angle so that a nearby bright IR source
 is also covered in the same slit, which may also serve as a decent background illumination
 for the absorption line survey. We measured the slit P.A. as accurate as possible
 using our own imaging at Mauna Kea, but, since the slit length of CRIRES is long,
 there is chance that the sources are not precisely in the slit. In such a case,
 we would appreciate if the observers could pay attention to the following possibilities
  - small tweaking of the slit P.A. at the site, so that two source are properly
 centered in the slit, - if this is not possible, we will put the priority to the
 primary source (unambiguously addressed in OBs and finding chart). Please centerd
 the primary source on the slit. In this case, a slight off-centering of the secondary
 source is acceptable.   2) Centering objects on the slit  Beacuse two sources are
 to be covered in one slit, we would like to put the middle of the two sources at
 the center of the slit, instead of putting the primary source at the center of the
 slit. The offsets are shown in the finding chart, and also below.   3) Spectroscopic
 standard
The order of the execution of each OBs is not very cretical, but the calibration
 star HR 6879 is meant to be observed after the object (therefore earlier R.A.).
 R.A.).

Special Calibration Information

1) Can we ask for the matched dark frames for the flat-field images? (dark
 frames with same integration time with the flat-field exposure)
Usually, the dark current is negligible, but we feel more confortable if we have
 matched dark frames because our observation aimes quite high      signal to noise
 ratio (over 500), and it would not take 1 minute or so.

ToO Information

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ToO Activators List

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Do the README file and the instrument comments of the telluric stars OBs include the required S/N/pixel of the spectrum of the telluric star, its spectral type and allowed spectral range?

Do any OBs include wavelength or flatfield calibrations?

If you are observing Moving Targets, have you attached suitable ephemeris files to your OBs?

```
N/A
```

If the slit viewer guide star is different from the target, are the RA and DEC offsets accurate to within 0.05 arcsec and do they take into account the relative proper motion between the two objects?

```
N/A
```

If you have preferences which OBs should be executed first for objects at similar RA, did you make use of the User Priority field in the OBs?

Last creation of page: Tue Oct 6 15:40:20 2009
If you have comments, please contact usd-help@eso.org