REDSHIFT-INDEPENDENT DISTANCES IN THE NASA/IPAC EXTRAGALACTIC DATABASE: METHODOLOGY, CONTENT, AND USE OF NED-D

Journal Article · Sun Jan 01 04:00:00 EST 2017 · Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/153/1/37· OSTI ID:22664059

Steer, Ian ^[1]; Madore, Barry F. ^[2]; Mazzarella, Joseph M.; Schmitz, Marion; Chan, Ben H. P.; Ebert, Rick; Helou, George; Baker, Kay; Chen, Xi; Frayer, Cren; Jacobson, Jeff; Lo, Tak; Ogle, Patrick; Pevunova, Olga; Terek, Scott ^[3]

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1. 268 Adelaide St. E., Ste. 188, Toronto, ON M5R 2G2 (Canada)
2. Observatories of the Carnegie Institution for Science, 813 Santa Barbara St., Pasadena, CA 91101 (United States)
3. Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)

Estimates of galaxy distances based on indicators that are independent of cosmological redshift are fundamental to astrophysics. Researchers use them to establish the extragalactic distance scale, to underpin estimates of the Hubble constant, and to study peculiar velocities induced by gravitational attractions that perturb the motions of galaxies with respect to the “Hubble flow” of universal expansion. In 2006 the NASA/IPAC Extragalactic Database (NED) began making available a comprehensive compilation of redshift-independent extragalactic distance estimates. A decade later, this compendium of distances (NED-D) now contains more than 100,000 individual estimates based on primary and secondary indicators, available for more than 28,000 galaxies, and compiled from over 2000 references in the refereed astronomical literature. This paper describes the methodology, content, and use of NED-D, and addresses challenges to be overcome in compiling such distances. Currently, 75 different distance indicators are in use. We include a figure that facilitates comparison of the indicators with significant numbers of estimates in terms of the minimum, 25th percentile, median, 75th percentile, and maximum distances spanned. Brief descriptions of the indicators, including examples of their use in the database, are given in an appendix.

• OSTI ID: 22664059
• Journal Information: Astronomical Journal (Online), Journal Name: Astronomical Journal (Online) Journal Issue: 1 Vol. 153; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
CATALOGS
COMPARATIVE EVALUATIONS
COSMOLOGY
DISTANCE
EXPANSION
GALAXIES
INDICATORS
RED SHIFT
UNIVERSE
VELOCITY