Datasets:

astro-legacy-archive
/

ebhis-hi

MOM0 float32	HPXINDEX int64	RA2000 float64	DEC2000 float64	GLON float64	GLAT float64
89,869,656,019,620,070,000	0	192.90971	27.137879	45	89.954315
93,083,062,314,679,140,000	1	192.848771	27.173011	135	89.954315
92,413,618,063,037,960,000	2	192.809314	27.118776	225	89.954315
91,172,594,890,720,670,000	3	192.870236	27.08366	315	89.954315
83,304,982,263,564,860,000	4	192.960461	27.111756	22.5	89.908629
98,318,602,434,613,610,000	5	192.944087	27.180153	67.5	89.908629
93,500,252,210,629,440,000	6	192.878112	27.218195	112.5	89.908629
87,588,829,098,961,530,000	7	192.801218	27.203564	157.5	89.908629
94,255,942,154,353,380,000	8	192.758525	27.144844	202.5	89.908629
93,411,218,157,058,650,000	9	192.775007	27.076468	247.5	89.908629
91,177,133,674,720,130,000	10	192.840933	27.038474	292.5	89.908629
89,777,015,567,910,170,000	11	192.917719	27.053084	337.5	89.908629
83,462,238,814,615,900,000	12	193.00597	27.086062	15	89.862944
87,032,819,262,934,750,000	13	193.010141	27.15691	45	89.862944
98,103,678,697,708,980,000	14	192.973922	27.220119	75	89.862944
92,938,876,757,859,100,000	15	192.906978	27.258726	105	89.862944
86,927,626,786,482,160,000	16	192.827273	27.26236	135	89.862944
88,074,909,995,461,770,000	17	192.756234	27.230042	165	89.862944
98,135,942,766,914,440,000	18	192.712936	27.170458	195	89.862944
97,372,996,046,447,180,000	19	192.708952	27.099601	225	89.862944
99,522,585,259,214,370,000	20	192.745281	27.036461	255	89.862944
96,276,967,671,507,980,000	21	192.812149	26.99793	285	89.862944
98,164,600,437,980,790,000	22	192.891666	26.994305	315	89.862944
89,989,318,069,094,190,000	23	192.962595	27.026555	345	89.862944
83,626,400,298,689,360,000	24	193.050196	27.060693	11.25	89.817258
83,839,089,827,966,350,000	25	193.064822	27.130796	33.75	89.817258
95,739,051,398,827,870,000	26	193.048189	27.200545	56.25	89.817258
91,222,477,534,249,620,000	27	193.002779	27.259313	78.75	89.817258
88,211,135,088,096,700,000	28	192.935484	27.298128	101.25	89.817258
86,763,298,176,641,270,000	29	192.856572	27.311059	123.75	89.817258
84,993,568,241,038,130,000	30	192.778109	27.296128	146.25	89.817258
92,314,195,823,607,940,000	31	192.712091	27.255619	168.75	89.817258
99,429,373,061,458,030,000	32	192.66859	27.195722	191.25	89.817258
98,792,395,189,161,820,000	33	192.654203	27.125578	213.75	89.817258
94,835,771,810,284,300,000	34	192.67107	27.055875	236.25	89.817258
104,601,818,806,144,200,000	35	192.716572	26.997214	258.75	89.817258
101,407,288,926,710,800,000	36	192.783762	26.958503	281.25	89.817258
99,388,110,589,090,860,000	37	192.862435	26.945613	303.75	89.817258
94,087,699,283,117,600,000	38	192.940663	26.960497	326.25	89.817258
88,934,754,476,661,670,000	39	193.006589	27.0009	348.75	89.817258
85,471,591,916,330,020,000	40	193.093911	27.03548	9	89.771573
85,375,582,560,992,620,000	41	193.114743	27.104498	27	89.771573
102,149,987,041,040,920,000	42	193.110606	27.17587	45	89.771573
100,564,069,061,322,870,000	43	193.08186	27.242609	63	89.771573
83,245,247,995,851,050,000	44	193.031284	27.298167	81	89.771573
84,562,330,984,531,360,000	45	192.963819	27.337086	99	89.771573
88,671,742,499,204,630,000	46	192.886088	27.355537	117	89.771573
88,924,973,221,220,970,000	47	192.805739	27.351705	135	89.771573
87,523,421,351,248,400,000	48	192.730685	27.325965	153	89.771573
98,863,291,698,920,820,000	49	192.668305	27.280852	171	89.771573
99,115,994,655,355,830,000	50	192.624716	27.220803	189	89.771573
96,516,080,664,223,680,000	51	192.604166	27.151713	207	89.771573
96,447,224,848,045,830,000	52	192.608625	27.080355	225	89.771573
96,849,030,377,300,300,000	53	192.637611	27.013713	243	89.771573
97,826,461,030,021,070,000	54	192.688253	26.958297	261	89.771573
98,706,439,768,148,800,000	55	192.755586	26.919509	279	89.771573
104,217,077,697,352,830,000	56	192.833036	26.90113	297	89.771573
94,719,469,868,344,670,000	57	192.913062	26.904947	315	89.771573
90,490,290,751,081,020,000	58	192.987877	26.93059	333	89.771573
90,609,759,286,508,650,000	59	193.05019	26.975561	351	89.771573
90,210,768,507,021,300,000	60	193.137365	27.010348	7.5	89.725888
89,793,719,348,559,350,000	61	193.162278	27.078378	22.5	89.725888
99,049,153,144,480,070,000	62	193.166585	27.149833	37.5	89.725888
99,018,138,120,483,770,000	63	193.149954	27.219844	52.5	89.725888
96,393,858,951,680,100,000	64	193.113482	27.283634	67.5	89.725888
81,822,224,862,811,260,000	65	193.059631	27.336842	82.5	89.725888
85,873,687,716,654,220,000	66	192.992068	27.375823	97.5	89.725888
94,502,531,826,137,960,000	67	192.915412	27.397906	112.5	89.725888
100,510,843,902,445,490,000	68	192.834918	27.401576	127.5	89.725888
89,715,029,500,382,670,000	69	192.756113	27.386579	142.5	89.725888
90,333,007,811,750,920,000	70	192.684402	27.353946	157.5	89.725888
101,753,476,759,785,830,000	71	192.624695	27.305915	172.5	89.725888
102,544,658,938,854,380,000	72	192.581065	27.245776	187.5	89.725888
97,400,888,457,420,600,000	73	192.556469	27.177644	202.5	89.725888
98,328,911,455,635,640,000	74	192.552551	27.106171	217.5	89.725888
99,165,006,485,675,570,000	75	192.569539	27.036231	232.5	89.725888
95,143,854,968,387,140,000	76	192.60624	26.972582	247.5	89.725888
93,848,128,893,564,750,000	77	192.66013	26.919547	262.5	89.725888
94,893,878,800,789,010,000	78	192.727534	26.880725	277.5	89.725888
100,761,796,436,369,080,000	79	192.803873	26.858744	292.5	89.725888
96,383,356,416,611,580,000	80	192.883978	26.855092	307.5	89.725888
90,222,845,542,740,790,000	81	192.962427	26.870018	322.5	89.725888
90,709,832,436,822,310,000	82	193.033909	26.90251	337.5	89.725888
93,230,476,037,638,320,000	83	193.093575	26.950368	352.5	89.725888
93,893,701,451,512,800,000	84	193.180664	26.985261	6.428571	89.680202
93,653,761,626,053,020,000	85	193.208457	27.052456	19.285714	89.680202
101,658,566,916,076,200,000	86	193.218787	27.123474	32.142857	89.680202
102,934,053,180,854,500,000	87	193.211105	27.194759	45	89.680202
92,937,478,179,068,580,000	88	193.185761	27.262733	57.857143	89.680202
91,983,392,357,228,740,000	89	193.144	27.323978	70.714286	89.680202
84,782,743,483,481,850,000	90	193.0879	27.375409	83.571429	89.680202
94,978,470,827,383,590,000	91	193.020272	27.414434	96.428571	89.680202
95,260,869,393,861,570,000	92	192.94452	27.439081	109.285714	89.680202
101,740,247,435,880,430,000	93	192.864471	27.448104	122.142857	89.680202
100,892,893,406,772,070,000	94	192.784171	27.441046	135	89.680202
89,862,627,941,295,330,000	95	192.70768	27.418266	147.857143	89.680202
94,280,879,078,071,340,000	96	192.638861	27.380914	160.714286	89.680202
104,322,753,958,921,630,000	97	192.58118	27.330877	173.571429	89.680202
103,819,239,206,051,380,000	98	192.537531	27.270679	186.428571	89.680202
101,301,674,237,793,140,000	99	192.510088	27.203353	199.285714	89.680202

End of preview. Expand in Data Studio

EBHIS H I Column Density

This dataset contains LAMBDA's native HEALPix bintable for the atomic neutral-hydrogen column-density map derived from the Milky-Way portion of the Effelsberg-Bonn H I Survey. All six source fields and RING row order remain unchanged.


Pixelisation	Galactic HEALPix, NSIDE 1024, RING
Rows	12,582,912 scalar source pixels
Angular resolution	10.8 arcmin
Velocity selection	\|Vlsr\| < 600 km/s

How to use

python -m venv .venv && .venv/bin/pip install datasets huggingface_hub pyarrow

from datasets import load_dataset
dataset = load_dataset("astro-legacy-archive/ebhis-hi", "NHI_HPX", split="train[:1]", columns=["MOM0", "HPXINDEX"])
row = dataset[0]
print(row["MOM0"], row["HPXINDEX"])

8.986965601962007e+19 0

import json
from huggingface_hub import hf_hub_download
import pyarrow.parquet as pq
path = hf_hub_download("astro-legacy-archive/ebhis-hi", "NHI_HPX.parquet", repo_type="dataset")
print(json.loads(pq.read_schema(path).metadata[b"healpix_map"])["schema"])

astro-legacy-archive/healpix-map

The embedded document records geometry, units, and per-column coverage codes. Validity is determined by matching a value’s source-width bits to the applicable coverage.codes[*].source_bits; sentinel values are not hard-coded.

Dataset structure

source column	type	source unit
`MOM0`	float32	`cm^(-2)`
`HPXINDEX`	int64	`deg`
`RA2000`	float64	`deg`
`DEC2000`	float64	`deg`
`GLON`	float64	`deg`
`GLAT`	float64	empty string

Source row i is RING HEALPix pixel i; no column is removed or added. The unusual source units—deg on HPXINDEX and an empty GLAT unit—are preserved rather than corrected. MOM0, RA2000, DEC2000, GLON, and GLAT each contain 5,718,326 measured NaNs. HPXINDEX contains 5,718,326 measured int64 minimum values at the same rows. All six populations are recorded separately as measured coverage codes, without semantics.

Provenance and physics

LAMBDA provides the product description and download table. The pinned source is NHI_HPX.fits, 553,659,840 measured bytes, SHA-256 6cedd70f62695f531ba77fbbcff556c9c5bafc73224ef2353cb68365e148b354.

LAMBDA documents a 1420 MHz frequency, 1417.5–1423.5 MHz bandpass, 10.8-arcmin resolution, 4.7 × 10^18 cm^-2 sensitivity, and a column-density integration over |Vlsr| < 600 km/s. The page says all-sky coverage; the file's shared NaN rows and coordinate limits are reported as delivered without attempting to reconcile that statement.

Winkel et al. (2016) separates the EBHIS uncertainty budget into thermal noise, intensity calibration (typically about 2.5%), baseline errors, and stray-radiation correction errors. Column densities below approximately 2 × 10^20 cm^-2 show excess uncertainty attributed to baseline and stray radiation, while the wider confidence intervals show that the systematic errors are not perfectly normally distributed. These estimates describe ensemble distributions and do not necessarily apply to an individual sight line; for small brightness temperature the paper directs users to measure the local RMS for that sightline.

At low Galactic latitude, broad emission masks make baseline interpolation uncertain. Winkel et al. also documents solar radio-frequency interference, standing-wave-like ripples around strong continuum sources, and data loss or increased noise from flagging. LAMBDA's sibling Zenith Equal Area image NHI_ZEA.fits is not converted here.

Licensing and credit

The source states verbatim:

Permission is granted for publication and reproduction of this material for scientific, scholarly, educational, and private non-commercial use by the Argelander-Institut für Astronomie (AIfA) and the Max-Planck-Institut für Radioastronomie (MPIfR), Germany.

Publications must include:

The EBHIS data are based on observations performed with the 100-m telescope of the MPIfR at Effelsberg. EBHIS was funded by the Deutsche Forschungsgemeinschaft (DFG) under the grants KE757/7-1 to 7-3.

Citations

@article{Winkel2016,
  author  = {Winkel, B. and Kerp, J. and Flöer, L. and others},
  title   = {The Effelsberg-Bonn HI Survey: Milky Way gas. First data release},
  journal = {Astronomy and Astrophysics},
  volume  = {585},
  pages   = {A41},
  year    = {2016},
  doi     = {10.1051/0004-6361/201527007}
}

@article{Kerp2011,
  author  = {Kerp, J. and Winkel, B. and Ben Bekhti, N. and others},
  title   = {The Effelsberg-Bonn HI Survey (EBHIS)},
  journal = {Astronomische Nachrichten},
  volume  = {332},
  pages   = {637},
  year    = {2011}
}

Errata and requests

To report an erratum, propose a correction, or ask a question about this dataset, open a Discussion or Pull Request in its Community tab; posting requires a free Hugging Face account. Dataset requests and archive-wide questions may be posted in the README space's Community tab or the Community tab of any dataset. Confirmed corrections are made in the source conversion tools and published by rebuilding the dataset.

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