Proposed Science Verification Targets for the Long BaselineCampaign – Additional Information
ALMA Technical Note Number: 5Status: FINAL
Prepared by:
EOC Management
ALMA Deputy Director

Organization:

Date:

ALMA24 June 2014

Atacama Large Millimeter/Submillimeter Array
Alonso de Córdova 3107
Vitacura - Santiago Chile

MEMORANDUM
To: ALMA Science Advisory Committee
From: EOC Management; ALMA Deputy Director
Date: 11/16/2014
Subject: Proposed Science Verification Targets for the Long Baseline Campaign: AdditionalInformation
The characterization and commissioning of baselines longer than 5 km with ALMA (hereafter,
the “Long Baseline Campaign”) is scheduled to take place starting in 2014 September andcontinue through the end of November. In addition to testing the integration of the various
procedures necessary to calibrate and image sources (e.g. online/offline WVR corrections,band-to-band phase transfer, bandwidth transfer, baseline determination, fast switching etc.) a
dedicated Science Verification (SV) effort is essential to the success of the overall Long Baseline
Campaign in demonstrating these capabilities to the wider astronomical community.
In conjunction with members of the JAO, nine proposed SV targets have been selected, of
which we intend to select five SV targets for our final list. These targets span the five ALMA
Science Categories and have been checked for conflicts against existing accepted Cycle2
proposals. The final list will be announced in a news item on the Science Portal well in advanceof the start of the Long Baseline Campaign. After the campaign, the successfully demonstrated
SV data products (raw and calibrated data), scripts, and/or CASA guide will be made publicly
available to the community.
The proposed SV targets are listed in the table below.
Suitability of the targets for SV and demonstration of the long baseline capability.
The specific requirements for selection of suitable targets were as follows:• Possible bands are 3, 4 and 6 (higher frequencies will be done on test targets not SV
since the outcome of higher frequency work at long baselines is too unknown prior tothe campaign and is too weather dependent).
• There should be comparison data in the literature (i.e. imaging with otherinterferometers).
• Targets should be suitable for imaging on 5-10 km baselines. Only the 12-m array will beused (no ACA).
• At least one of the targets (out of the 5 selected) should be suitable for combining 10km baselines at Band 3 and 5-km baselines at Band 6.
• Targets suitable for observation in both spectral line and continuum are ideal.

•

•
•

Largest angular scales should be no larger than 2'' in Band 3 and 1'' in Band 6 (however
the source extent (for the given spectral line) can be larger, up to ~20-30''' at Band 3 or15'' in Band 6).
Targets should be observable during night time in October. An LST of 0-4h is ideal (buta suitable LST range could be 21h - 8h).
As recommended by the ASAC, targets cover a range of the science categories.

The individual targets chosen were considered suitable for SV as follows:• MG0414+0534 is a well-studied gravitationally lensed radio-loud quasar at z~2.6.
There is suitable comparison data in the literature from PdBI, VLA, MERLIN, VLBI andHST, in particular CO J=3-2 PdBI imaging with 2''x0.9'' resolution, 22.5 GHz VLA
imaging at 0.08'' resolution, and VLBI 8.4 GHz imaging at 2.55x1.13 mas resolution (e.g.
Barvainis et al, 1998, ApJ, 492, 13; Katz et al. 1997, ApJ, 475, 512; Ros et al. 2000, A&A,362, 845). It is a good target for demonstrating similar-resolution (~0.06'') imaging at
two frequencies (Bands 3 and 6) and would be observed in a mixed mode spectral setup
demonstrating both spectral line (CO J=3-2) and continuum long baseline capabilities.
•SDP.81 is a high-z (z~3), lensed, ultra-luminous starburst galaxy first detected in theHerschel-ATLAS Survey. It has been detected in CO J=5-4 and H2O emission lines with
the PdBI by Omont et al. 2013, A&A, 551, 115, at ~2.8''x1.8'' angular resolution. It is agood target for demonstrating similar-resolution (~0.06'') imaging at two frequencies(Bands 3 and 6) and would be observed in a mixed mode spectral setup demonstrating
both spectral line (CO J=5-4 and H2O) and continuum. Together with MG0414+0534
above, these are the most suitable high-z targets within the LST range required forobservation during the campaign.

•3C 138 is a strongly polarized (12%) quasar with an extent of ~1'', making it ideal forthe demonstration of the polarization capability. It is also a good target for
demonstrating similar-resolution (~0.06'') imaging at two frequencies (Bands 3 and 6). In
addition it could be used to test self-calibration of relatively weak and extended sources.
There is suitable comparison data in the literature including e.g. MERLIN, VLA and VLBI
observations from Akujor et al, 1993, A&A, 274, 752, with angular resolution of e.g ~0.06'' at 22.5 GHz.

•NGC 1068 is a well-known nearby Seyfert 2 galaxy whose central regions, containing acircumnuclear molecular disk, starburst ring or spiral, stellar bar and radio jet, havebeen well studied with other interferometers such as the SMA, PdBI and OVRO.
Suitable comparison data in the literature includes Krips et al. 2011, ApJ, 736, 37; Tsai etal. 2012, ApJ, 746, 129; Schinnerer et al., 2000, ApJ, 533, 850, with angular resolutions
ranging from 0.5'' to 1''. It is a good target for demonstrating similar-resolution (~0.06'')
imaging at two frequencies (Bands 3 and 6). It would be observed in a mixed mode
spectral setup demonstrating both spectral line and continuum, and could also be used
as a test of the polarization capability.

•Orion KL, source I, is a massive young star with associated very strong compact SiO
maser emission. The extent of the emission is ~0.15'' and so will be resolved with 10km
baselines at Band 3. Suitable comparison data in the literature, from the VLA, VLBA,VLBI, Hat Creek millimeter array and ALMA, includes e.g. Plambeck et al. 1990, ApJ, 348,

L65; Greenhill et al. 1998, Nature, 396, 650; Kim et al. 2008, PASJ, 60, 991; Greenhill et al.
2004, IAUS, 221, 155; Niederhofer et al. 2012, A&A, 548, A69; Zapata et al. 2012, ApJ, 754,
L17, with angular resolutions ranging from 0.2 mas to 2.6''x1.5'' (~1.8''x1.2'' for the
published ALMA data).
•HL Tau, a young star with a circumstellar disk, has suitable comparison data from theVLA (0.08'' angular resolution at 1.3cm), eMerlin and CARMA (0.13'' angular resolution
at 1.3mm) (e.g. Greaves et al. 2008, MNRAS, 391, 74; Kwon et al. 2011, ApJ, 741, 3). It is asuitable continuum-only target for Band 3 and 10km baselines. Potentially, 13CO could
be added as a gas tracer that does not force the window too high in band 3 to sufferfrom the O 2 line.

•Juno, an asteroid often used as an ALMA calibrator, is the most suitable ephemeris
target that is within the LST range required for observation during the campaign. It
would be observed with a TDM spectral setup in Band 6.

•Mira is a well-studied AGB star and is a prototypical Mira variable. With a propermotion of 240 mas/yr it would provide a possible astrometric test. It is also a goodtarget for demonstrating similar-resolution (~0.06'') imaging at two frequencies (Bands 3and 6). It would be observed in a mixed mode spectral setup demonstrating both
spectral line (SiO) and continuum long baseline capabilities.

Potential sources of conflict with Cycle 2 programs. The table also lists of Cycle 2Science Goals on, or including (in the field), these targets. A full set of information on the Cycle
2 projects can be found in an accompanying spreadsheet. Note that this includes any Science
Goal on these targets. Those which may potentially constitute a conflict are highlighted, wherea potential conflict is defined as being a factor of two or less difference in angular resolution
irrespective of band or spectral setup.
We note that the matched resolution for 10km baselines in Band 3 and 5km baselines in Band6, for Briggs 0.5 weighting, is ~0.06''.
Four out of the nine proposed SV targets have at least one A/B-ranked Cycle2 Science Goalthat has an angular resolution within a factor of two of the aim for the long baseline campaign,
though in no case are these the same band, target line, or spectral setup.

SV Long Baseline Target Parameters
TargetNameCoord.
(J2000)Band &Res. ('')

Cycle 2 Science Goals on or including this target

Line/Continuum

Sci.
Cat.

Project CodeBandLine

Res.
('')

A/B/
C
Rank

MG0414+053404h

3&60.06

spectral line
(CO(3-2)) &continuum;
mixed mode1

2013.1.01110.S

7

continuum

0.22

B

SDP.8109h

60.03
0.06

spectral line
(CO J=5-4,H2O) &continuum;mixed mode1

2013.1.01005.S

7spectral line([NII]) only

0.3

C

2013.1.01005.S

8spectral line([CII]) only

0.2

C

3C 13805h

3&60.06

continuum;polarization;
TDM, full
pol2

None

...

...

...

...

NGC106802h

3&60.06

spectral line
(CO J=1-0,
CO J=2-1,HCN&HCO+) &continuum;polarization;
mixed mode2

2013.1.00055.S

9spectral line
(CO(6-5), H
CN, HCO+,SiO)

0.1

C

2013.1.00055.S

3

spectral line
(HCN,HCO+, CS,SiO)

0.5

C

2013.1.00490.S

7continuum;polarization0.35

C

2013.1.00014.S

9continuum &spectral line
(CO(6-5))0.1

B

2013.1.00014.S

7continuum &spectral line
(HCN)

0.15

B

2013.1.00129.S

6

spectral line
(HCO+(32))

0.5

C

2013.1.00129.S

7

spectral line
(N2H+(3-2))

0.5

C

2013.1.00111.S

6

spectral line
(H and He
recombination lines) &continuum

0.2

B

2013.1.00221.S

3

spectral line
(SiO,CH3OH,0.5

BCS) &continuum
2013.1.00221.S

4

spectral line
(SiO) &continuum

0.5

B

2013.1.00221.S

6

spectral line
(SiO, 13CO,C18O) &continuum

0.5

B

2013.1.00221.S

6

spectral line
(SiO, CS) &continuum

0.5

B

2013.1.00368.S

8spectral line([CI])

0.3

B

2013.1.01151.S

3

spectral line
(13CN, CN,CH3OH,CS)

3.4

B

2013.1.01151.S

3

spectral line
(CN, C17O,HC3N,H2CO)

3.4

B

2013.1.00060.S

3

spectral line
(CN, HC3N,CS,CH3OH)

1.1

B

2013.1.00279.S

3

spectral line
(C3H2,H13CN,C2H, HCN,CS, SO,HC3N)

1.0

B

2013.1.00279.S

3

spectral line
(HCO+,HNC,HC3N,H3CN,CH3CCH,H2CS)

1.0B

2013.1.00279.S

3

spectral line
(N2H+,C34S,HNCS, SO2)

1.0

B

2013.1.00188.S

7

spectral line
(HCN,HCO+)

0.6

B

2013.1.00188.S

7

spectral line
(HNC) &0.6

B

continuum

Orion KLHL Tau05h04h

3

3

0.06

0.06

spectral line
(SiO); mixed
mode

continuum;
TDM, dual
pol or mixedmodewith 13CO

33

2013.1.00188.S

6

spectral line
(HCN,HCO+)

0.6

B

2013.1.00188.S

6

spectral line
(HNC) &continuum

0.6

B

2013.1.00727.S

8

spectral line([CI])

0.5

B

2013.1.00504.S9spectral line
(H2O)

0.17

C

2013.1.00451.S

9spectral line
(H2S)

0.9

B

2013.1.01034.S

4

spectral line
(CH3CN)

0.3

B

2013.1.01034.S

4

spectral line
(CH2DCN)

0.3

B

2013.1.00367.S

9spectral line
(13CO, SiO,CH3OH) &continuum

0.18

B

2013.1.00048.S

7

spectral line(o-H2O)

0.13

A

2013.1.00048.S

8

spectral line
(p-H2O)

0.13

A

2013.1.00048.S

8

spectral line
(p-H2O,SiO)

0.13

A

2013.1.00048.S

8

spectral line
(p-H2O)

0.12

A

2013.1.00553.S

6

spectral line(O18O)

3.0

B

2013.1.00553.S

6

spectral line
(O18O)

3.0

B

2013.1.00553.S

6

spectral line
(O18O)

3.0

B

2013.1.00553.S

6

spectral line
(O18O)

3.0

B

2013.1.00553.S

6

spectral line
(O18O)

3.0

B

2013.1.00355.S

7

continuum
only;polarization

0.122

B

Juno

08h

6

0.03
0.06

continuum;
ephemeris;
TDM

4

None

...

...

...

...

Mira

02h

3&6

0.06

spectral line
(SiO) &continuum;
mixed mode5

2013.1.00156.S

7

spectral line
(HNC, TiO,AlO, CO,HCN)

0.12

B

2013.1.00323.S

7

spectral line
(CO(3-2)) &continuum

0.2

C

2013.1.00047.S

7

spectral line
(CO(3-2)) &continuum

0.32

B

2013.1.00047.S

9continuum
only

0.17

B

None

...

...

...

...

Betelgeuse

06h

3&6

0.06

spectral line&continuum;
mixed mode

5

The Science Categories are: 1. Cosmology and the high redshift universe, 2. Galaxies andgalactic nuclei, 3. ISM, star formation and astrochemistry, 4. Circumstellar disks, exoplanets andthe solar system, 5. Stellar evolution and the Sun).
Catherine Vlahakis
ALMA Deputy Program Scientist (EOC)
Anthony Remijan
ALMA Program Scientist (EOC)