[daip] How to find our the center velocity!
Eric Greisen
egreisen at nrao.edu
Wed Feb 26 16:57:52 EST 2014
Karl Menten wrote:
> Eric
>
> What you recommend below doesn’t work. Maybe the fact that the observe file didn’t have \\FISVTL but rather //FISF cards causes this. (see previous email originating from Ken Sowinski).
>
> Here’s the SETJY input:
> AIPS 1: SETJY Task to enter source info into source (SU) table.
> AIPS 1: Adverbs Values Comments
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: INNAME '20030412' Input image name (name)
> AIPS 1: INCLASS 'LINE' Input image name (class)
> AIPS 1: INSEQ 6 Input image name (seq. #)
> AIPS 1: INDISK 2 Input image disk unit #
> AIPS 1: SOURCES *all ' ' Sources to modify.
> AIPS 1: QUAL -1 Source qualifier -1=>all
> AIPS 1: BIF 0 Low IF # for flux density
> AIPS 1: EIF 0 High IF # for flux density
> AIPS 1: ZEROSP *all 0 I,Q,U,V flux density (Jy)
> AIPS 1: (at 1 GHz if OPTYP='SPEC)
> AIPS 1: SPECINDX 0 Spectral index
> AIPS 1: SPECURVE *all 0 Spectral index curvature
> AIPS 1: OPTYPE 'VCAL' ' ' => use other adverbs
> AIPS 1: for required operation
> AIPS 1: 'SPEC' => as ' ' but ZEROSP
> AIPS 1: is at 1 GHz not freq of BIF
> AIPS 1: 'CALC' => determine
> AIPS 1: 3C286/3C48/1934 fluxes from
> AIPS 1: standard formulae
> AIPS 1: 'VCAL' set velocity of
> AIPS 1: ref channel
> AIPS 1: 'REJY' => reset source
> AIPS 1: fluxes to zero.
> AIPS 1: 'REVL' => reset velocity
> AIPS 1: to zero
> AIPS 1: 'RESE' => reset fluxes &
> AIPS 1: velocities to zero.
> AIPS 1: CALCODE ' ' New calibrator code:
> AIPS 1: '----' => change to blank
> AIPS 1: SYSVEL 0 Velocity of source (km/s)
> AIPS 1: RESTFREQ 0 0 Line rest frequency (Hz)
> AIPS 1: VELTYP ' ' Velocity type 'LSR,'HELIO'
> AIPS 1: VELDEF ' ' Velocity definition 'RADIO',
> AIPS 1: 'OPTICAL'
> AIPS 1: FREQID 0 FQ table entry to use for
> AIPS 1: velocity information and
> AIPS 1: 'CALC' option
> AIPS 1: APARM *all 0 (1): Pixel to which SYSVEL
> AIPS 1: refers ( 0=>1)
> AIPS 1: (2): Only for 'CALC' option:
> AIPS 1: <= 0 => use best VLA
> AIPS 1: values (2010)
> AIPS 1: 1 => use VLA 1999.2
> AIPS 1: values = default before
> AIPS 1: 2/15/10 in SETJY
> AIPS 1: 2 => use VLA 1995.2
> AIPS 1: values
> AIPS 1: 3 => use oldest VLA
> AIPS 1: values (1990)
> AIPS 1: 4 => use Baars values
> AIPS 1: (any) for 1934-638, the
> AIPS 1: ATCA value of 30Jul94.
> AIPS 1: (3): Only for 'CALC' option:
> AIPS 1: multiply the calculated
> AIPS 1: fluxes by APARM(3) with
> AIPS 1: 0 -> 1
> AIPS 1: (4): Only for 'CALC' option:
> AIPS 1: Use channel APARM(4)'s
> AIPS 1: frequency for flux
> AIPS 1: 0 -> center
>
> When I run it, I get:
>> go
> SETJY1: Task SETJY (release of 31DEC12) begins
> SETJY1: Copied SU file from vol/cno/vers 2 13 2 to 2 13 1
> SETJY1: Using CL table 1 to obtain time dependent freq offsets
> SETJY1: ZABORS: signal 10 received
> SETJY1: ABORT!
> AIPS 1: Resumes
>
> When I enter (guessed, but reasonable) values for SYSCEL, RESTFREQ, VELTYP, and VELDEF, I get the same error message.
>
> Any idea?
>
> Karl
>
> On 10 Feb 2014, at 18:11, Eric Greisen <egreisen at nrao.edu> wrote:
>
>> Karl Menten wrote:
>>> Eric,
>>> I retrieved an 2003 dataset (AV262) from the VLA archival database and have problems (after imaging) to convert to velcoity units. ALTSWTCH gives:
>>> AIPS 1: ALTERNATE AXIS PARAMETERS ARE INVALID: USE ALTDEF
>>> The problem is that I don’t know what to input as AXVAL.
>>> When running LISTR/optype ‘SCAN’ I get:
>>> ——-
>>> Source summary
>>> Velocity type = 'LSR ' Definition = 'OPTICAL '
>>> ID Source Qual Calcode RA(2000.0) Dec(2000.0) IFlux QFlux UFlux VFlux No. vis
>>> 1 1229+020 : 0000 B 12:29:06.6997 02:03:08.598 0.000 0.000 0.000 0.000 34865
>>> IF( 2) 0.000 0.000 0.000 0.000
>>> 2 10077+13565 : 0000 A 10:07:41.4980 13:56:29.600 0.498 0.000 0.000 0.000 81301
>>> IF( 2) 0.500 0.000 0.000 0.000
>>> 3 09480+13167 : 0000 09:47:57.3801 13:16:43.700 0.000 0.000 0.000 0.000 233651
>>> IF( 2) 0.000 0.000 0.000 0.000
>>> 4 1331+305 : 0000 A 13:31:08.2879 30:30:32.958 2.450 0.000 0.000 0.000 50475
>>> IF( 2) 2.472 0.000 0.000 0.000
>>> 5 09583+32240 : 0000 A 09:58:20.9496 32:24:02.209 0.000 0.000 0.000 0.000 3505
>>> IF( 2) 0.000 0.000 0.000 0.000
>>> 6 10160+30343 : 0000 10:16:02.2700 30:34:18.599 0.000 0.000 0.000 0.000 7020
>>> IF( 2) 0.000 0.000 0.000 0.000
>>> ID Source Freq(GHz) Velocity(Km/s) Rest freq (GHz)
>>> 1 1229+020 23.9634 0.0000 0.0000
>>> IF( 2) 23.6874 0.0000 0.0000
>>> 2 10077+13565 23.9634 0.0000 0.0000
>>> IF( 2) 23.6874 0.0000 0.0000
>>> 3 09480+13167 23.9634 0.0000 0.0000
>>> IF( 2) 23.6874 0.0000 0.0000
>>> 4 1331+305 23.9634 0.0000 0.0000
>>> IF( 2) 23.6874 0.0000 0.0000
>>> 5 09583+32240 23.9619 0.0000 0.0000
>>> IF( 2) 23.6859 0.0000 0.0000
>>> 6 10160+30343 23.9619 0.0000 0.0000
>>> IF( 2) 23.6859 0.0000 0.0000
>>> Frequency Table summary
>>> Type Q to stop, just hit RETURN to continue localhos LISTR(31DEC12) 261 09-FEB-2014 22:36:59 Page 4
>>> File = 20030412 .CH 0 . 3 Vol = 1 Userid = 261
>>> FQID IF# Freq(GHz) BW(kHz) Ch.Sep(kHz) Sideband Bandcode
>>> 1 1 23.96337600 3125.0002 2294.9221 1 VLA_K
>>> 2 23.68737200 3125.0002 2294.9221 1 VLA_K
>>> ----
>>> You see the (incorrect) zeros in the Velocity(Km/s) and Rest freq (GHz) columns. The data look OK.
>>> Question: Is the center velocity somewhere stored in the header and, if yes, how can I retrieve it?
>> SETJY has new options 'VCAL' and 'VANT' which will compute the velocity from the various frequencies, dates, start time, etc. It does require a
>> multi-source file and would normally be done early in the reductions.
I have loaded your data to disk and tried SETJY. I do not know your
line rest frequency - that is your science and you should know it.
Setting an arbitrary value near the center of the observation I get
AIPS 1: Found in Version=OLD
SETJY1: Task SETJY (release of 31DEC12) begins
AIPS 1: Resumes
>SETJY1: Using CL table 1 to obtain time dependent freq offsets
SETJY1: / Calculating velocity of reference pixel
SETJY1: BIF = 1 EIF = 1 /Range of IFs
SETJY1: '2253+161 ' IF = 1 velocity = 237.04 (km/sec calcd)
SETJY1: '22540+16089 ' IF = 1 velocity = 237.04 (km/sec calcd)
SETJY1: '23192+17116 ' IF = 1 velocity = 232.75 (km/sec calcd)
SETJY1: '0137+331 ' IF = 1 velocity = 208.51 (km/sec calcd)
SETJY1: RESTFREQ = 4.29000008D+10 /Rest frequency (Hz)
SETJY1: Appears to have ended successfully
SETJY1: thuban 31DEC12 OLD: Cpu= 0.1 Real= 2 IO= 4
Note that 31DEC12 had a patch to this part of the code for machines
running as architecture LINUX (32-bit) fairly far along in 31DEC13.
Are you running the Bonn-standard copy of aips or your own copy? Why
are you running OLD? I have made the LINUX version of 31DEC12 and
(soon) 13 up to do with patches in Bonn. I will also do the LNX64
version when the LINUX version 13 finishes. The MNJ did make a LINUX
specific fix to this operation in SETJY (and CVEL).
Eric Greisen
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