Chandra Archive and Target FAQs

1. What is the Chandra Observation Catalog (OCAT)?
2. How do I find out which targets have been observed, or will be observed, with Chandra?
3. How do I download Chandra data?
4. What is the status of my observation?
5. Has my data been processed (or re-processed?)
6. When does data on my favourite target become public?
7. Where do I find scheduling Information?

Q: How do I find out which targets have been observed, or will be observed, with Chandra?
Search the OCAT. There are two ways to do this:

1. The Chandra Target Search Form is a simple HTML-based search routine with access to abstracts, observation planning and status information for each target. It is possible to use SIMBAD to search for a target, and DSS and ROSAT images are given for most fields.
2. ChaSeR is a Java application which must be installed on a user's local machine or system. ChaSeR can be used to search the Archive as well as to download data. A limited version of this tool is also available via a web interface, WebChaSeR.

Q: How do I download Chandra data?
There are several ways to download data:

1. Using ChaSeR, observations may be searched for using a variety of criteria and then specific products may be selected and downloaded. Note that more than one ObsID may be downloaded at a time. This is also the interface through which proprietary data may be downloaded. Note that ChaSeR, a Java application, must first be installed on a user's machine or network.

   An example showing how to install and use ChaSeR is given in the How To Download Chandra Data From The Archive thread.

2. WebChaSeR is a web-based version of ChaSeR, so no installation is required. However, it currently has limited capabilities; for example, data products can only be batch downloaded in either Primary or Secondary bundles.

3. Chandra Data can also be downloaded using the Provisional Search and Retrieve Interface. However, you need to know the ObsID in advance to be able to use the Provisional Search and Retrieve Interface. The ObsID for a given target can be found from the Target Search Form.

Q: Has my data been processed (or re-processed?)
The Processing Status Tool gives information on pipeline processing.

1. If you know the ObsID of the observation in question, go to the Processing Status Tool.

2. If you don't know the ObsID, use the Target Search Form to search for a target using the Simbad name resolver or search by PI name. Click on the status link to get the appropriate Processing Status Table.

   Note: the Processing Status Table only has information on observations where data has been received by the CXC. If no data has been received there will be no link from the Target Search Form.

1. If you know the ObsID of the observation in question, go to the Processing Status Tool.

2. If you don't know the ObsID, use the Target Search Form to search for a target using the Simbad name resolver or search by PI name. Click on the status link to get the appropriate Processing Status Table.

1. The Short Term Schedule provides a detailed list of each week of observing once planned (1-2 weeks ahead of current time) and back to the beginning of the mission.
2. The Long Term Schedule lists the long-term plan forward from the current date including primarily observations which are time constrained

Last modified: 08/11/05

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