ALMA CSV tests than can use SiO masers
J=2-1 (for triggering 32-bit data storage)
Email sent to ramestica on 2014-02-14
Hi Rodrigo,
Here are the recommended sources and DelayCal commands. To get the highest spectral resolution, I would use single-polarization. But I don't know how well-tested that mode is, and you may have other reasons to use dual-polarization. In any case, the best daytime source is w_hya, available before 11:30AM local time. The best nighttime sources are vy_cma and r_leo. In the afternoon, there is ik_tau, but it may not be nearly as bright as the other three. It depends on their brightness phase, which I have not bothered to calculate.
The frequencies below will roughly center the lines in their windows on Feb 5. For simplicity, I have taken the midpoint of their LSR velocities (+20km/s), and used the online VLA Dopset tool (as the VLA velocity will be within ~1 km/s of the ALMA velocity). The spws are sufficiently broad (58 MHz = 200 km/s) that the lines will still be captured at any time of the year.
Feature rest frequency SKY FREQ for v=+20 km/s
SiO v=1 86.24337 GHz 86.22142
continuum 86.0
SiO v=2 85.64045 GHz 85.61866
continuum 84.5
23:30LST = 16:00 on Feb 4
Source LSR RA Current transit time (Chile time)
vy_cma +20 07:22 Midnight (nighttime) 300K at 30m
r_leo +1 09:47 02:20 (nighttime) 1500Jy at 30m, 9K at 14m
w_hya +41 13:49 06:19 (morning source) 9.2K at 14m
ik_tau +35 03:53 11:23 (afternoon source) 1.7K at 14m
Example commands:
1) Single-polarization (narrowest channels):
DelayCal -b 3 -s w_hya -n FDM -w 32 -T -P 1 -#84.5, 85.61866, 86, 86.22142
2) Dual-polarization (more common usage):
DelayCal -b 3 -s w_hya -n FDM -w 32 -T -# 84.5, 85.61866, 86, 86.22142
If the basebands are mapped starting from the first frequency provided,
then the strongest line (v=1) should be in the 4th baseband. The v=2 line
may also be strong, depending on the source.
I have not set the subscan duration, so it should default to 30 sec.
Also, I have inserted a Tsys. If you do not want it, then please remove it.
Regards,
Todd
J=6-5 (for spectral line regression of a maser line that can be placed in either sideband)
Email sent to wdent on 2013-09-24
Hi,
Here is the information for a Band 6 SiO J=6-5 maser regression SB.
Maser line frequencies from CDMS
v=1 258.70739 GHz
v=2 256.89839
We should place spws on each of the v=1 and v=2 lines since some objects (like VYCMa) are much stronger in the v=2 transition. These lines can be observed in both sidebands because the max LO is (275-10 = 265 GHz), so the v=1 line will appear at a maximum IF of ~6.3 GHz in LSB, which is still in the "good" 6-10 GHz range. The attached uptimes plot (made with the au command below) shows that the 4 sources listed below are the minimum to cover all RA's from ALMA. If one of these turns out to be a bust, I include 3more possibilities at the bottom of this message. Below I took the coordinates from simbad, which should be reasonable (since these are stars!). The velocities are from the mm SiO detections.
Sources: Coordinates in J2000 velocity (LSRK) line flux density
J=6-5 v=1 J=7-6 v=1
omi Cet (Mira) 02 19 20.79210, -02 58 39.4956 +47 km/s 32 Jy
R Leo 09 47 33.48791, +11 25 43.6650 +4 40 23
W Hya 13 49 01.99810, -28 22 03.4881 +43 156
R Aqr 23 43 49.46201, -15 17 04.1385 -25 25
au.buildMinorPlanetPlot(bodies='Mars',
cals=['Mira 02:19:20.792 -02:58:39.49',
'VYCMa 07:22:58.32877 -25:46:03.2355',
'RLeo 09:47:33.487 +11:25:43.66',
'WHya 13:49:01.998 -28:22:03.48',
'RAqr 23:43:49.46 -15:17:04',
'VXSgr 18:08:04.048 -22:13:26.6'])
VY CMa 07 22 58.32877, -25 46 03.2355 +20 80Jy(v=2) 43
VX Sgr 18 08 04.04831 -22 13 26.6327 +5 5-4 = 6Jy
IRC+10011 01 06 25.98 +12 35 53.0 +8 30 Jy
--
ToddHunter - 2014-02-04