NED Local Volume Sample
The NED Local Volume Sample (NED-LVS) is a subset of ~2 million objects in NED with distances out to 1000 Mpc. The distances selected for NED-LVS are based on both redshifts (~99%) and redshift-independent distances, where the latter are prioritized at distances less than 200 Mpc. Photometry from all-sky surveys (GALEX, 2MASS, and AllWISE) that have been joined into NED are also extracted, with ~90% of NED-LVS objects having at least one measurement. These fluxes are used to derive physical properties (SFR and stellar mass) and to estimate the completeness relative to expected local luminosity densities.
The galaxies in NED-LVS can be used for studies in many areas of astrophysics that include: star formation, galaxy evolution, large scale structure, galaxy environments, and searches for the electromagnetic counterparts to gravitational wave events, to name a few. The data in NED are updated regularly, and NED-LVS will be updated concurrently. Consequently, NED-LVS will continue to provide an increasingly complete sample of galaxies for a multitude of astrophysical research areas for years to come.
To estimate the completeness of the galaxy census per unit volume in NED-LVS, we define completeness as the ratio of the total luminosities of galaxies to the total luminosity expected from integrating under published galaxy luminosity functions. The completeness relative to NIR luminosities (which traces a galaxy's stellar mass) is roughly 100% at D<30 Mpc and remains moderate (70%) out to 300 Mpc. For brighter galaxies (>L✱), NED-LVS is ~100% complete out to 400 Mpc. The Figure below gives the density of NED-LVS objects in distance shells where completeness in the shell is given in the parentheses. For more details about NED-LVS see Cook et. al (2023)↗.
(~1 GB FITS table)
Latest Update to NED-LVS
The January 2025 version of NED-LVS includes new objects ingested by NED and the removal of newly identified non-galaxy contaminants. This updated version contains a total of 2.07M objects, an increase of 203K (10%) over the previous version, where 30K of the newly added objects (after contaminant removal; see below) are from the literature and 173K originate from the Dark Energy Spectroscopic Instrument Early Data Release (DESI-EDR; DESI Collaboration, 2024↗). Each release of NED-LVS is accompanied by an additional round of vetting of both newly ingested objects and those from the previous version to ensure that this sample will provide a robust and highly complete census of the local Universe. Listed below are details of redshift updates and contaminants identified and removed by our additional vetting for this version of LVS.
- 151K "stars" (0.8% were in the previous version): objects determined to be stars in our Galaxy via one or more of the following reasons:
- stellar spectroscopic classifications and redshifts from DESI-EDR consistent with being members of the Milky Way.
- objects with high stellar probabilities from either GAIA astrophysical parameter metrics or the machine learning catalog of Tachibana et al. (2019)↗ based on PanSTARRS1 objects.
- 5K parts of galaxies ("PofGs"; 20.8% were in the previous version): objects that reside in or near large angular-sized galaxies that have been determined via visual inspection and supporting metadata (redshifts, publication classifications, etc.) to be a sub component of a galaxy. These “PofGs” can be many types of physical objects such as HII regions, planetary nebulae, star clusters, etc. During our vetting, we have flagged additional spectroscopic fiber position sources (e.g., SDSS and DESI-EDR) that are located outside of the central part of the galaxy as “PofGs”, unless there is no other object with a redshift for that unique galaxy. Note: PofGs were flagged for future updates to the NED database, but omitted from the LVS galaxy sample.
- ~1200 updated redshifts (27.2% were in the previous version): objects with fiducial redshifts that were determined by the NED team to be questionable and were replaced with more reliable measurements. Of the objects with updated redshifts, 859 now have distances beyond the 1000 Mpc limit currently imposed on NED-LVS and have been removed from the sample.
- ~600 "Unmatched data" (74.3% were in the previous version): objects that contain data for existing galaxies in NED that should be merged. Generally these are additional observations of large nearby galaxies whose provided positions or names are discrepant enough from an existing object to result in an ambiguous match. Only obvious matches via visual inspection have been identified and flagged. Note that these flags will help to make these crossmatches in the NED database at a later date, and that the unmatched data has been removed from LVS (without the loss of vital distance information) to avoid duplication of unique galaxies.
- Caveats: In general, any "Unmatched data" and "PofGs" in a galaxy sample would result in over-countering the true number of distinct galaxies in the local volume. Identification of these objects is an on-going process and each successive release of NED-LVS will identify and remove additional contaminants.
Update History
July 2023 (labeled "2019-09-22v2")
This version of NED-LVS contains updated redshifts for 271 objects with more reliable measurements. Of the objects with updated redshifts, 69 have distances beyond the 1000 Mpc limit currently imposed on NED-LVS and have been removed from the sample.
NED-LVS Columns
Click here for column descriptions of NED-LVS
| Column | Data Type | Unit | Description |
|---|---|---|---|
| objname | S | -- | Prefered object name in NED |
| ra | D | deg | Right ascension [J2000] |
| dec | D | deg | Declination [J2000] |
| objtype | S | -- | Prefered object type in NED |
| z, z_unc | F | -- | Fiducial redshift [heliocentric] |
| z_tech | S | -- | Technique used to measure redshift [SPEC, PHOT, UNKN, INFD, MOD, NULL] |
| z_qual | B | -- | Qualifier flag indicating reliability of redshift [True=unreliable] |
| z_qual_flag | B | -- | Boolean flag indicating that the z_qual flag has been updated in NED-LVS |
| z_refcode | S | -- | Reference code for the publication that provided the redshift |
| ziDist, ziDist_unc | F | Mpc | Redshift-independent distance computed as the weighted average of measurements in either the primary or secondary indicators |
| ziDist_method | S | -- | Method used to measure the redshift-independent distance when a single method is used to compute the weighted average, otherwise "Wavg" when a mixture of methods are used [Cepheid, SNIa, TRGB, Wavg, etc.] |
| ziDist_indicator | S | -- | Measurement type indicator for redshift-independent distance [Primary or Secondary] |
| ziDist_refcode | S | -- | Reference code for the publication that provided the distance when a single measurement was chosen, otherwise "Mix" indicates an average of multiple measurements was used [refcode or Mix] |
| DistMpc, DistMpc_unc | F | Mpc | Selected distance used in NED-LVS |
| DistMpc_method | S | -- | Method used in the selected distance [Redshift or zIndependent] |
| ebv | F | mag | Foreground MW reddening E(B-V) from Schlafly & Finkbeiner (2011) |
| A_FUV_MWext | F | mag | MW extinction in GALEX FUV-band assuming Fitzpatrick et al. (1999) |
| A_NUV_MWext | F | mag | MW extinction in GALEX NUV-band assuming Fitzpatrick et al. (1999) |
| A_J_MWext | F | mag | MW extinction in 2MASS J-band assuming Fitzpatrick et al. (1999) |
| A_H_MWext | F | mag | MW extinction in 2MASS H-band assuming Fitzpatrick et al. (1999) |
| A_Ks_MWext | F | mag | MW extinction in 2MASS Ks-band assuming Fitzpatrick et al. (1999) |
| A_W1_MWext | F | mag | MW extinction in WISE W1-band assuming Fitzpatrick et al. (1999) |
| A_W2_MWext | F | mag | MW extinction in WISE W2-band assuming Fitzpatrick et al. (1999) |
| A_W3_MWext | F | mag | MW extinction in WISE W3-band assuming Fitzpatrick et al. (1999) |
| A_W4_MWext | F | mag | MW extinction in WISE W4-band assuming Fitzpatrick et al. (1999) |
| m_FUV, m_FUV_unc | F | mag | Apparent magnitude in GALEX FUV-band in AB system |
| m_NUV, m_NUV_unc | F | mag | Apparent magnitude in GALEX NUV-band in AB system |
| Lum_FUV, Lum_FUV_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in GALEX FUV-band |
| Lum_NUV, Lum_NUV_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in GALEX NUV-band |
| GALEXphot | S | -- | Flag indicating which catalog was used for GALEX photometry [ASC, MSC, z0MGS] |
| m_J, m_J_unc | F | mag | Apparent magnitude in 2MASS J-band in Vega system |
| m_H, m_H_unc | F | mag | Apparent magnitude in 2MASS H-band in Vega system |
| m_Ks, m_Ks_unc | F | mag | Apparent magnitude in 2MASS Ks-band in Vega system |
| Lum_J, Lum_J_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in 2MASS J-band |
| Lum_H, Lum_H_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in 2MASS H-band |
| Lum_Ks, Lum_Ks_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in 2MASS Ks-band |
| tMASSphot | S | -- | Flag indicating which catalog was used for 2MASS photometry [PSC, XSC, LGA] |
| m_W1, m_W1_unc | F | mag | Apparent magnitude in WISE W1-band in Vega system |
| m_W2, m_W2_unc | F | mag | Apparent magnitude in WISE W2-band in Vega system |
| m_W3, m_W3_unc | F | mag | Apparent magnitude in WISE W3-band in Vega system |
| m_W4, m_W4_unc | F | mag | Apparent magnitude in WISE W4-band in Vega system |
| Lum_W1, Lum_W1_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in WISE W1-band |
| Lum_W2, Lum_W2_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in WISE W2-band |
| Lum_W3, Lum_W3_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in WISE W3-band |
| Lum_W4, Lum_W4_unc | D | erg/s | Monochromatic luminosity (nu*F_nu) in WISE W4-band |
| WISEphot | S | -- | Flag indicating which catalog was used for WISE photometry [Pfit, APER, z0MGS] |
| SFR_W4, SFR_W4_unc | F | Msun/yr | Star formation rate using W4 luminosity scaling relationship |
| SFR_hybrid, SFR_hybrid_unc | F | Msun/yr | Star formation rate using a FUV+W4 luminosity scaling relationship |
| SFR_flag | B | -- | Boolean flag on SFR measurements to indicate an overestimated value due to early-type galaxy determination based on IR or UV-IR colors [True=colors indicate an early-type galaxy] |
| Mstar, Mstar_unc | F | Msun | Stellar mass using a W1 luminosity scaling relationship |
| MLratio | F | Msun/erg/s | The mass-to-light ratio used to calculate Mstar |
Publication Version of NED-LVS (2021-09-22)
The version of NED-LVS that corresponds to the analysis of Cook et. al (2023)↗ can be downloaded here.
Citation of NED-LVS
If you use the NED-LVS in your research, please cite both the publication (Cook et. al (2023)↗) and the Digital Object Identifier (DOI): 10.26132/NED8
Last update: Feb 7, 2025
