Survey Specifications

We use the on-the-fly mapping technique on Mopra for our observations. Data are read out every two seconds and the telescope is driven so that the beam is close to Nyquist sampled at the highest observing frequency (27.5 GHz). Two orthogonal scanning directions (Galactic longitude and latitude) are used to observe a single map, which is 0.5 degrees on a side. Each 0.25 square degree takes 4 hours to observe, resulting in each beam area receiving approximately one minute on-source integration.

The survey is now complete and we have observed a total of 100 square degrees over three seasons. The first season, incorporating 6 weeks of observations (12-15 hours per day) was completed in February/March 2008. The second season took place from January to March 2009. The final season took place from January to March, 2010.

Using the Mopra spectrometer (MOPS), we were able to cover 16 different frequency bands simultaneously. The bands that we covered, and spectral lines within those bands are shown in the following table. The last column gives an indication of any detections made in the 2008 observations. Note: methanol lines that are known to be masers are indicated with either a "I" or "II" for Class I and Class II, respectively.

Band number Frequency range
covered (MHz)
Spectral line Frequency (MHz) Detections?
16 19518 - 19655 H69α 19591.11 Many/extended
15 19932 - 20069 CH3OH(21,1-30,3)II 19967.396 SgrB2, extended
14 20691 - 20828 NH3 (8,6)
NH3 (9,7)
NH3 (7,5)
C6H (71,8-6-1,7)
20719.221
20735.452
20804.83
20792.872
G19.61-0.23
No
No
No
13 21036 - 21173 NH3 (11,9)
NH3 (4,1)
21070.739
21134.311
G19.61-0.23
No
12 22145 - 22277 H2O maser 22235.253 Many
11 22278 - 22415 C2S (12-21) 22344.030 SgrB2, l=2, extended
10 23037 - 23174 CH3OH (92,7-101,10)II
NH3(2,1)
23121.024
23098.819
No
SgrB2
09 23382 - 23519 H65α
CH3OH (101,9-92,8)
23404.28
23444.778
Yes
No
08 23658 - 23795 NH3(1,1)
NH3(2,2)
23694.4709
23722.6336
Many/extended
Many/extended
07 23796 - 23933 NH3(3,3) 23870.1296 Many/extended
06 24900 - 25037 CH3OH (32,1-31,2)I
CH3OH (42,2-41,3)I
CH3OH (22,0-21,1)I
CH3OH (52,3-51,4)I
CH3OH (62,4-61,5)I
24928.715
24933.468
24934.382
24959.079
25018.123
G305.4 (M); SgrB2, GC (T)
G305.4 (M); SgrB2, GC (T)
G305.4 (M); SgrB2, GC (T)
G305.4 (M); SgrB2 (T)
G305.4, G305.2 (M); SgrB2 (T)
05 25038 - 25175 CH3OH (72,5-71,6)I
NH3(6,6)
25124.872
25056.025
G305.4, G305.2 (M); SgrB2 (T)
l=359-03.5 Extended
04 26556 - 26693 HC5N (10-9) 26626.533 SgrB2, l=2 Extended
03 26832 - 26969 H62α
CH3OH (122,10-121,11)I
26939.17
26847.205
Many/Extended
No
02 27246 - 27383 HC3N (3-2) 27294.078 Many/Extended
01 27384 - 27521 NH3(9,9)
CH3OH (132,11-131,12)I
27477.943
27472.501
l=0, SgrB2 Extended

Last modified 6th June 2017.