ID                   = CDS/P/HI
creator_did          = ivo://CDS/P/HI
obs_collection       = HI
obs_title            = HI composite survey
obs_description      = Composite all-sky map of neutral hydrogen column density (N_HI), formed from the Leiden/Dwingeloo HI survey data (Hartmann & Burton 1997) and the composite N_HI map of Dickey and Lockman (1990). The two datasets are not matched in sensitivity or resolution: note that discontinuities exist in the constructed composite map. A pixel mask is provided to indicate which dataset was used for each location on the sky. Hartmann & Burton provide a velocity integrated (-450 km/s < V_lsr < +400 km/s) HI brightness temperature map in Galactic coordinates, sampled every 0.5 degrees. This entire data set was converted to N_HI by multiplying by their factor of 1.8224e18 K km s-1 cm-2 and then interpolated to pixel centers appropriate for HEALPix Nside=512. Since the Leiden/Dwingeloo survey does not have sky coverage for declinations < -30 deg., the lower resolution Dickey & Lockman map was also interpolated to HEALPix and used to fill in the coverage gap. The Dickey & Lockman N_HI map is itself a composite of several surveys which had been merged and averaged onto 1 deg. bins in Galactic coordinates. Their map includes emission between -250 km/s < V_lsr < 250 km/s (excluding the LMC and SMC). The Leiden/Dwingeloo Survey data were obtained from the CDS. The Dickey & Lockman map was obtained from NCSA ADIL. This original HEALPix file is distributed and maintained by LAMBDA.
obs_copyright        = Composite HI map by LAMBDA
obs_copyright_url    = http://lambda.gsfc.nasa.gov/product/foreground/fg_HI_get.cfm
client_category      = Image/Gas-lines/HI
client_sort_key      = 06-05
hips_creation_date   = 2011-02-14T12:00Z
hips_release_date    = 2019-05-05T06:29Z
hips_builder         = Aladin/HipsGen v10.123
hips_creator         = CDS
hips_version         = 1.4
hips_order           = 3
hips_frame           = galactic
hips_tile_width      = 64
hips_tile_format     = jpeg fits
dataproduct_type     = image
moc_access_url       = http://alasky.u-strasbg.fr/HI/Moc.fits
hips_status          = public master clonableOnce
hips_copyright       = CNRS/Unistra
obs_ack              = We acknowledge the use of the Legacy Archive for Microwave Background Data Analysis (LAMBDA), part of the High Energy Astrophysics Science Archive Center (HEASARC). HEASARC/LAMBDA is a service of the Astrophysics Science Division at the NASA Goddard Space Flight Center.
prov_progenitor      = HEASARC/LAMBDA
bib_reference        = 1990ARA&A..28..215D
bib_reference_url    = http://adsabs.harvard.edu/abs/1990ARA%26A..28..215D
t_min                = 44239
t_max                = 47892
obs_regime           = Radio
em_min               = 0.21
em_max               = 0.21
hips_pixel_scale     = 0.01431
hips_initial_fov     = 120.0
hips_initial_ra      = 266.4168166
hips_initial_dec     = -29.0078249
hips_order_min       = 0
hips_pixel_bitpix    = -32
moc_sky_fraction     = 1
hips_estsize         = 1112337
hipsgen_date         = 2019-05-05T06:29Z
hipsgen_params       = out=/asd-volumes/sc1-asd-volume10/HI UPDATE
hips_service_url     = https://alasky.cds.unistra.fr/HI
hips_service_url_1   = https://alaskybis.cds.unistra.fr/HI
hips_status_1        = public mirror clonableOnce
moc_type             = stmoc
moc_time_order       = 25
moc_time_range       = 1
moc_order            = 3
obs_initial_ra       = 266.4168166
obs_initial_dec      = -29.0078249
obs_initial_fov      = 7.3290376785437985
TIMESTAMP            = 1721288415898