Atacama Large Millimeter/submillimeter ArrayExpanded Very Large Array

Robert C. Byrd Green Bank TelescopeVery Long Baseline Array

The ALMA Observing Preparation Tool

NRAO / North American ALMA Science Center

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Video versions of this material:

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Click here

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Registering with User Portal• To register for the user portal, go to either:

• http://almascience.org/• http://almascience.nrao.edu/ (saves one step)

• Go to the User Portal to access:• ALMA info and news• Call for Proposals• ALMA tools and documentation• Helpdesk• Project Tracker• ALMA Science Archive

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Launch the Application

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A couple of dialog boxes will pop up

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Hover over these icons to get help• New Proposal (Phase I)• Open project from Archive• …• New Phase I Science Goal…• Sensitivity Calculator …• Help!

Contextual help on proposal workflow

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• Be alert to the presence of sliders, some information may be off-screen

Tips

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• Stippled edges can be dragged to resize panes

Tips

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• Arrowheads maximize and minimize panes

Tips

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A walk through of a simple example• Observe molecular gas in NGC 1097

• Use CO (1-0) emission line– Rest frequency: 115.2712

GHz– Band 3 (2.6 mm)

• Size of NGC 1097 is 9’ x 6’ • The field of view for a single

pointing at 115 GHz is ~ 45”• Single pointing of the nucleus

During ES, up to 50 pointing mosaics are allowed.

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NGC 1097 from S4G, Sheth et al. 2010

Synthesized beam w/400m baseline

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Proposal Preparation Workflow – Using the Contextual help

Click through the tabs and follow the instructions on the left.

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Fill out these relevant fields

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Proposal Title

Abstract

Fill out these relevant fields

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{Fill out these relevant fields

Click here to set PI and co-Is

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Type in the name or username

An error may pop up

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• If you get stuck on any step, look for the “?” Icon

• Click on it to get help.

Finding Help

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…as a single PDF file

Attaching the Sci / Tech Justification…

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At any point you can check whether your proposal passes validation

Validation is required before proposal can be submitted

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Click on this turn-key to continue

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Press on Science Goal tab to create a science goal

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What is a Science Goal in the OT?• A science goal is:

– One correlator / front end setup in one ALMA band• spectral windows, rest freq, polarization products,

line/continuum modes– Subject to one set of control parameters

• spatial resolution, sensitivity, dynamic range– Using one mapping strategy

• Mosaic or single-pointing– And one calibration strategy

• User or system-defined– Applied to an arbitrary set of sky targets (field centers)

• Each with its own LSR velocity

• In ES all windows in one science goal must have the same bandwidth and channel spacing

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Describe your science goal if you wish – for the technical assessors (not required)

Enter in Source name

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Make sure and double check the coordinates.

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Check the velocity used -> observing frequency.

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Red text indicates incorrect or missing value

Click on Spatial Tab to visualize observations

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Clicking here opens the visualizer panelPress Query to get the image from pre-loaded servers - or - Load your own image* (Galactic coordinates won’t work yet)

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Enter frequency

Placing beams on an image (the graphical method)

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For Calibration Set up: Unless you have a strong reason for choosing User-defined calibration, then leave this as System-defined calibration.

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Currently supported modes for Cycle 0

Press here to add a line

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A window that can search Splatalogue will open.

e.g. Type in “CO”

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Double click on the transition

Transition moves into this window

Press here to accept selection

Now, the line list will be limited to those that can be observed at same time!

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Your chosen Line is now loaded into the Setup:

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Click on Spectral Tab to visualize observations

Atmospheric transmission

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Band 3

LO RangeSidebands

LO CO line

Press here to change resolution

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Trade-off between bandwidth & resolution

Select correlator mode

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Can add up to 4 spectral windows – must have same resolution and bandwidth in Cycle 0Location of windows is constrained

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Summary:A very versatile tool with lots of options

Note that the colors can be changed from the Preferences:

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Request the resolution and sensitivity you need for your Science Goal

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Back to our example of NGC 1097

To get a 10σ detection on the faintest emission in the map requires ~10 mJy/beam in a 10 km/s channel.

The ALMA correlator gives 1.275 km/s channels; we will bin 8 channels to get to 10 km/s.

So required sensitivity in one correlator channel ~ 10 mJy/bm * sqrt (8) ~ 28 mJy/beam

Nobeyama maps of NGC 1097 (Kohno et al. 2003)

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Back to our example of NGC 1097

1.4”~ 110pcSufficient to resolve the ring

Press here to get an idea of how long it will take to do this

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ALMA with 16 x 12m antennas is very fast!• BUT be aware that your UV-coverage may not be ideal – we recommend that you use simdata to check

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Back to our example of NGC 1097

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Time allocation for the proposal will be the Total Estimated time.

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Validation Step

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List of problems…

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See also: “known issues”http://almasw.hq.eso.org/almasw/bin/view/OBSPREP/

Cycle0KnownIssues

The Atacama Large Millimeter/sub-millimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

almascience.nrao.edu science.nrao.edu/alma

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