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.


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
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

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
Topic revision: r1 - 2014-02-04, ToddHunter
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding NRAO Public Wiki? Send feedback