CDA - Home

The Archive

Search and Retrieve Data

Advanced Data Services

Archive User Services

Chandra Aggregated Datasets

Publishing Chandra Results

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Data Analysis Links

CDA Status

The archive is fully functional.

Reprocessing Status

Reprocessing IV has been completed in December 2014.

Current Software Releases

ASCDSVER: 10.13
CALDBVER: 4.11.6

Announcements

Electrical Outage 11/05/21 - 11/06/21
2021-11-05
There will be a planned electrical outage Friday, November 5 2021, 5:30PM - Saturday, November 6 2021, 6:00PM EDT. During this time period ChaSeR and other archive interfaces will be unavailable.
Electrical Outage on 07/28/21
2021-07-26
There will be a planned electrical outage Wednesday, July 28 2021, 8:00PM - 10:00PM EDT. During this time period ChaSeR and other archive interfaces will be unavailable.
Downtime on 6/12/21
2021-06-10
Due to electrical work, the public interfaces of the Chandra Data Archive will not be available on Saturday 6/12 from 4 AM to 9 PM.
Repro V Begins
2020-10-26
The fifth major reprocessing of the archive (Repro V) has started! Details can be found here.
Past Notices

CXC → CDA

Welcome to the Chandra Data Archive

The Chandra Data Archive (CDA) plays a central role in the operation of the Chandra X-ray Center (CXC) by providing support to the astronomical community in accessing Chandra data. The CDA offers access to digital archives through powerful query engines, including VO-compliant interfaces and also serves as a permanent storage repository of contributed data products by authors who have processed images or other pertinent and valuable datasets that are essential to their publications.

Access the Chandra Data Archive

ChaSeR: Search & Retrieval interface for scientists, allowing specification of detailed selection criteria.
Chandra Fast Image is a simplified quick search tool for Chandra X-ray images and other data for the general public.
HTTPS: Direct access to the primary and secondary data products for all observations that are publicly released.
Cool Chandra Targets (formerly known as CATs): the list of approved Cool Chandra Targets (CCTs) programs, including the PI names, titles and abstracts.
Footprint Service: A search by position or object name overlays the footprints of Chandra Observations on Digital Sky Survey images, allowing further selection and retrieval of observations.
Chandra MOCs: Multi-Order Coverage maps (MOCs) for public Chandra observations, that can be used to visualize and analyze the global Chandra footprint.
Chandra Source Catalog: The most comprehensive catalog of sources detected in public Chandra Observations. The catalog can be accessed through CSCview.
CIAO Tools: There are command-line scripts for finding and downloading publicly-available Chandra data from the Archive. Please note that proprietary data can only be accessed using ChaSeR.
- find_chandra_obsid: The tool will find publicly available Chandra data that covers a circular region of sky (a point search can be used by setting the search radius to 0).
- download_chandra_obsid: The tool will download public data by ObsId from the Chandra archive.
Bibliography Search: Simultaneous browsing of the archive and the literature with a large repertoire of selection criteria.
Processing Status: Information on the processing status of Chandra observations.
Special Requests: Requests for services not available through standard interfaces such as requesting a custom dataset identifier; requesting a custom database query; and many others.
ZTF Annotation: Annotation of the Chandra archival observations with Zwicky Transient Factory objects
CDA Data Object Identifiers (DOIs): The new way to cite Chandra data in publications!