NGC 404 Chandra X-Ray Point Source Catalog with 74 Sources

74 highly significant X-ray point sources were detected in NGC 404, the closest face-on S0 galaxy to the Milky Way, as part of the Chandra Local Volume Survey. The catalog was created by combining a new 97-ks Chandra ACIS-S observation with archival data for a total exposure of ~123 ks, and originally published in Binder et al. (2013). It is sensitive to a limiting unabsorbed luminosity of ~6 x 10^35 erg/s in the 0.35-8 keV band.

Use Cases

• Analyzing the X-ray luminosity function (XLF) in soft (0.5-2 keV) and hard (2-8 keV) energy bands based on the cataloged sources.
• Cross-correlating X-ray sources with optical counterparts using overlapping Hubble Space Telescope observations mentioned in the description.
• Studying the population of low-mass X-ray binaries (LMXBs) and their relation to stellar mass, as the catalog identifies 21 likely LMXBs.
• Comparing the number of luminous (>10^37 erg/s) X-ray sources per unit stellar mass in NGC 404 to other galaxies.

Strengths

• Contains 74 highly significant X-ray point sources detected with a Poisson probability threshold (pns) less than 4 x 10^-6.
• Combines new and archival Chandra observations for a total exposure of ~123 ks, improving sensitivity.
• Provides limiting luminosities at the 90% completeness limit of 10^35 erg/s (soft band) and 10^36 erg/s (hard band), lower than previous studies.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment for specific analyses.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Data obtained from the Chandra X-Ray Observatory (Cycle 12 Obs. ID 12339 and archival IDs 870, 384) using the ACIS-S array, processed with ACIS-Extract and wavdetect.

Time Range

Observations from 1999 December 19, 2000 August 30, and 2010 October 21-22.

Freshness

Last updated 2026-03-13 19:27:40.704920; freshness should be verified.

Geography

NGC 404 galaxy.