NGC 2403 Central 3-kpc Region Chandra X-ray Source Catalog

58 X-ray point sources, supernova remnants, and H II regions detected in the central 6 kpc region of galaxy NGC 2403 using archival Chandra observations totaling ~180 ks. The catalog was created by NASA using data from four observations between 2001 and 2004, with sources identified via a signal-to-noise ratio threshold and spectral fitting. The distribution of X-ray emission is compared to morphology at other wavelengths using Spitzer, GALEX, and H-alpha imagery.

Use Cases

• Correlating X-ray source locations with optical H II regions and UV emission based on the multi-wavelength comparison described.
• Analyzing the spectral properties of composite supernova remnant and H II region emissions based on the described APEC model fitting.
• Studying the pervasiveness of X-ray emission in regions devoid of strong H-alpha and UV signals as noted in the description.
• Identifying discrete point sources in galactic surveys using the described signal-to-noise and count rate detection limits.

Strengths

• Includes 58 detected point sources with a defined signal-to-noise ratio (S/N) above 2.8 and a minimum of 5 sigma above background.
• Data is derived from four Chandra ACIS-S observations totaling approximately 180 ks of exposure time.
• Sources are classified by type ('Point Source', 'SNR', 'HII'), allowing for filtered analysis.
• Analysis covers a defined central region of 6 arcminutes (6 kpc) and the full Chandra energy range (0.3-8.0 keV).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• The description notes only 4 or 5 of the listed SNRs are likely 'truly' detected X-ray sources, indicating some entries may be marginal detections.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Source detection applied to merged and individual Chandra ACIS-S datasets using a tool described by Tennant (2006).

Time Range

Observations from 2001 Apr 17, 2004 Aug 13, 2004 Oct 03, and 2004 Dec 22.

Freshness

Last updated 2026-03-13 19:47:39.510474; freshness should be verified.

Geography

Central region of the nearby SAB(s)cd galaxy NGC 2403 (distance 3.2 Mpc).