IRAS16293Band9

Science target overview

IRAS 16293-2422 (d=160 pc; Chini 1981) is a well studied nearby Class 0 proto-binary system (consists of source A and source B) located in L1689 (i.e., Ophucus star forming cloud). The projected separation between source A and B is ~5" (Mundy et al. 1992; Chandler et al. 2005). Sub-arcsecond VLA and SMA centimeter and millimeter/submillimeter continuum images have spatially resolved source A as several sources associated with protostars and jets (Chandler et al. 2005; Pech et al. 2010) IRAS 16293-2422 hosts a large-scale quadrupolar outflow (Walker et al. 1988; Mizuno et al. 1990; Castets et al. 2001; Hirano et al. 2001; Garay et al. 2002; Stark et al. 2004; Yeh et al. 2008). The outflow aligned in the east-west direction is currently active and likely originated from source A. The origin of the other large-scale outflow aligned in the northeast-southwest direction is not clear. Previous molecular line studies with the SMA have revealed detailed structure and kinematics in the circumbinary envelope for each binary component. They imply gas infall and outflow motions (Chandler et al. 2005; Takakuwa et al. 2007; Yeh et al. 2008). In addition, IRAS 16293-2422 exhibits strong emission from number of complex organic molecules and other spices usually associated with hot cores in massive star-forming regions, especially toward source A (e.g., Blake et al. 1994; van Dishoeck et al. 1995; Bottinelli et al. 2004; Kuan et a. 2004; Schoier et al. 2004; Chandler et al. 2005; Huang et al. 2005; Bisschop et al. 2008; Jorgensen et al. 2011; Caux et al. 2011). Finally, source B shows narrow line width and no clear signature of outflow. This suggests that the source may be at the very young evolutionary stage; likely even before the mass accretion/loss processes start (Chandler et al. 2005; Bisschop et al. 2008; Jorgensen et al. 2011).

ALMA data description

This release of ALMA data is for observations taken in the Band 9 (602-720 GHz) using the FDM (Frequency Division Mode) setup. The observations target the CO 6-5 spectral line at a frequency of 691.473 GHz using four spectral windows of 1.875 GHz (813 km/s) wide with 3840 channels each. The channel width is 0.488 MHz (0.2 km/s), and because the observations use Hanning smoothing, the actual spectral resolution, and so the velocity resolution, is twice the channel spacing.

The data were taken during April 16 and 17, 2012. Four datasets are presented here with three of them having post-transit observations of the target source, while the other one has pre-transit. Each dataset lasts for 2.3 hours, including calibrations. The names of the datasets are

• uid___A002_X3d4118_X39b
• uid___A002_X3d55cb_X575
• uid___A002_X3d55cb_Xb50
• uid___A002_X3d55cb_X90c

The array was used in the corresponding Early Science Cycle 0 extended configuration. The expected angular resolution at the frequency of the CO (6-5) line is about 0.2 arcsec.

Download the data

To download all the data, follow one of the next links:

North America

Europe

East Asia

The links provide you with the option to download the following gzipped tar files:

IRAS16293_Band9_UnCalibratedMSandTablesForReduction - The file contains the raw data files in ALMA Science Data Model (ASDM) format already converted into CASA Measurement Sets (MS) using importasdm inside CASA. The tables that are needed to calibrate the data are also provided.

IRAS16293_Band9_CalibratedData - The fully-calibrated u-v data, ready for imaging.

IRAS16293_Band9_ReferenceImages - The final continuum and spectral line images.

Depending on how you want to proceed to work with the IRAS16293 data, download the file that corresponds.

NOTE: CASA 3.3 is required to follow this guide. For more information on obtaining the latest version of CASA, see http://casa.nrao.edu.

IRAS16293 data tutorials

This tutorial has been split into two parts - calibration and imaging:

1) IRAS16293 Band9 - Calibration : This section of the tutorial steps you through inspection and calibration of the basic visibility (u-v) data. To complete this part, you will need the data in the first directory: IRAS16293_Band9_UnCalibratedMSandTablesForReduction.

2) IRAS16293 Band9 - Imaging : This part of the tutorial focuses on constructing images from the fully calibrated visibility data. If you wish to skip calibration and proceed directly to this part of the tutorial, you will need the fully-calibrated visibility data in the IRAS16293_Band9_CalibratedData directory.

We also provide the final continuum and spectral line images in the IRAS16293_Band9_ReferenceImages directory.

How to Use A CASA Guide

For tips on using CASA and ways CASA can be run, see EVLA_Spectral_Line_Calibration_IRC+10216#How_to_Use_This_casaguide page.

To learn how to extract executable Python scripts from the tutorial, see Extracting_scripts_from_these_tutorials.

Within the guides:

# In CASA
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Tabs matter in python, make sure that commands that span more than one line and 
"for" loops keep their spacing. Sometimes (especially "for" loops) you may need to 
explicitly hit enter twice to get the command going.

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Last checked on CASA Version 3.0.0 (r9860).