Datasets:

juliensimon
/

first-radio-catalog

source_name stringlengths 16 16	ra_deg float64 0 360	dec_deg float64 -11.47 64.7	peak_flux_mjy float64 0.75 35.6k	integrated_flux_mjy float64 0.3 122k	rms_mjy float64 0.06 6.32	major_axis_arcsec float64 0 179	minor_axis_arcsec float64 0 49.4	position_angle_deg float64 0 180	deconv_major_arcsec float64 3.46 179	deconv_minor_arcsec float64 3.45 49.7	deconv_pa_deg float64 0 180	is_resolved bool 1 class
J030004.5+000946	45.019042	0.163014	1.04	0.97	0.104	0.39	0	119.1	6.17	5.28	169.1	true
J025940.7+001129	44.919921	0.191436	2.46	1.69	0.107	0	0	70.1	5.29	4.5	18.2	true
J030002.2+001048	45.009421	0.180008	0.83	1.82	0.104	10.85	2.29	153.9	12.52	6.04	156.2	true
J025947.4+001215	44.947592	0.204231	0.83	0.6	0.107	0.1	0	63.1	5.77	4.29	43.2	true
J025946.0+001230	44.941671	0.208344	1.56	1.1	0.107	0	0	170.3	5.78	4.2	177.5	true
J030001.2+001452	45.005271	0.247856	1.45	1.16	0.105	0	0	55.7	5.85	4.72	21.8	true
J030029.9+001211	45.124775	0.203161	1.1	2.3	0.108	12.29	0	20.2	13.81	5.25	18.9	true
J030040.0+001334	45.166708	0.226342	0.86	1.21	0.107	4.35	3.05	93.7	7.1	6.92	165.4	true
J030028.7+001505	45.119921	0.251461	1.77	2.06	0.108	4.16	0	136.7	7.37	5.46	151.2	true
J030029.1+001544	45.121446	0.262236	3.57	7.05	0.107	9.12	2.65	154	11.05	6.18	157.2	true
J030038.5+002113	45.160721	0.353814	7.75	8.64	0.105	2.29	1.52	69	6.61	5.83	5.8	true
J025911.0+001240	44.795967	0.211208	8.14	10.09	0.103	3.81	1.55	129.6	7.15	5.99	154.3	true
J025910.4+001253	44.793517	0.214856	0.81	0.55	0.103	0	0	95.1	4.97	4.74	129.7	true
J025942.8+001840	44.928658	0.311331	1.87	3.81	0.101	9.76	2.25	149.2	11.55	6.08	152.3	true
J025928.4+001808	44.868588	0.302361	1.23	0.68	0.106	0	0	92.6	4.61	4.16	174.7	true
J025931.4+001941	44.881138	0.3282	2.8	4.88	0.103	6.6	3.56	150.8	9.08	6.63	158.3	true
J025932.3+002300	44.884754	0.383478	1.36	1.67	0.1	4.79	0	102.8	7.28	5.81	110.5	true
J025924.4+002155	44.851879	0.365339	4.98	5.17	0.104	1.83	0	17.4	6.64	5.41	3.9	true
J030000.0+001928	45.000092	0.324656	1.95	1.77	0.098	1.52	0	5.4	6.57	4.76	2.3	true
J030020.4+002301	45.085329	0.383728	3.84	4.91	0.099	4.51	0	60.9	7.34	6.01	43.7	true
J030124.1+002453	45.350554	0.414983	0.93	1.7	0.107	8.78	1.39	142.7	10.68	5.92	146.8	true
J030143.9+002735	45.433233	0.459928	1.09	1.12	0.106	3.59	0	50.3	6.96	5.09	34.9	true
J030102.9+002331	45.262454	0.39205	6.06	10.43	0.107	7.17	2.63	141.3	9.4	6.32	148.2	true
J030118.5+002753	45.327142	0.464833	0.79	0.6	0.106	0	0	94	5.32	4.95	106.6	true
J030110.8+002906	45.295192	0.485097	10.14	11.29	0.105	2.66	0.71	58.6	6.64	5.79	16.8	true
J030109.4+002902	45.289246	0.483978	0.97	2.01	0.105	8.16	3.66	66.4	9.9	7.22	60.9	true
J030111.1+002906	45.296625	0.485194	0.79	6.48	0.105	32.68	5.77	85.3	33.13	8.61	85.2	true
J030127.0+002727	45.362783	0.457719	1.07	0.73	0.105	0	0	56.4	5.44	4.31	16.3	true
J030131.0+003421	45.37925	0.572528	0.75	1	0.097	4.97	0	92.4	7.34	6.33	94.5	true
J030123.5+003419	45.348258	0.572197	5.42	5.49	0.095	1.47	0	83.1	6.27	5.59	3.4	true
J030223.2+003341	45.597037	0.561597	17.7	17.94	0.111	1.22	0	63.2	6.38	5.49	4.9	true
J030218.2+003435	45.575975	0.576581	3.13	2.73	0.111	0.6	0	35.5	6.29	4.79	14.3	true
J030145.3+003252	45.439017	0.547783	0.8	0.45	0.098	0	0	92	4.47	4.3	109.7	true
J030159.6+003550	45.4987	0.597286	1.55	1.56	0.103	1.63	0	21.1	6.57	5.29	5.4	true
J030201.2+003646	45.505375	0.612994	1.04	1.21	0.103	3.42	0	91.1	6.4	6.3	102.1	true
J030208.0+003827	45.533633	0.641044	0.84	0.58	0.109	0	0	137.2	5.92	4.09	157.1	true
J030049.2+002944	45.205213	0.495644	3.05	2.88	0.107	1.26	0	66.8	6.1	5.35	19.4	true
J030041.2+003326	45.171863	0.557422	0.9	0.73	0.111	4.89	0	3.7	8.05	3.49	2.9	true
J030042.0+003355	45.175042	0.565436	1.15	0.79	0.112	0	0	81.9	5.34	4.41	2.5	true
J030102.5+003147	45.260679	0.529861	0.81	1.21	0.104	5.98	2.22	24.2	8.68	5.96	17.8	true
J030102.6+003404	45.261008	0.568003	7.98	8.85	0.101	2.39	1.48	23.3	6.8	5.64	5.1	true
J030111.6+003444	45.298654	0.579008	10.55	13.9	0.097	4.82	1.72	11.5	7.99	5.69	7.3	true
J030025.2+003224	45.1051	0.540083	7.72	7.69	0.107	0.69	0	146.6	6.41	5.37	177.5	true
J030022.9+003743	45.095492	0.628786	1.59	2.63	0.123	7.53	2.11	4.9	9.88	5.8	4	true
J030153.5+004209	45.473183	0.702572	1.59	1.42	0.103	0	0	61.1	6.04	5.14	12.1	true
J030137.1+004321	45.404583	0.722711	2.25	1.94	0.099	0	0	57.6	5.97	4.99	15.4	true
J030134.4+004521	45.393596	0.756025	4.61	6.27	0.104	4.37	2.25	106.7	7.14	6.58	135.4	true
J030134.9+004519	45.395442	0.755503	5.09	6.07	0.104	3.56	0	97.1	6.54	6.29	127.3	true
J030124.7+004545	45.353004	0.762739	1.27	1.77	0.106	4.23	3.14	12.6	7.66	6.27	5.1	true
J030125.3+004600	45.355471	0.766786	1.56	4.38	0.107	12.09	4.46	24.2	13.61	7.13	22.3	true
J030120.2+005241	45.334546	0.878092	7.39	7.01	0.137	0.4	0	80.2	6.08	5.4	5.4	true
J025853.6+003101	44.723333	0.517003	1.33	1.4	0.104	3.56	0	108.7	6.63	5.48	124	true
J025846.4+003230	44.693725	0.541925	1.06	0.6	0.1	0	0	57.1	5.57	3.51	39.5	true
J025919.1+002838	44.82995	0.477431	1.32	0.93	0.105	0	0	41.2	5.95	4.07	22	true
J025908.3+002907	44.784971	0.485289	1.28	1.17	0.108	0	0	110.5	6.01	5.23	169	true
J025908.1+003328	44.784125	0.557947	1.37	0.86	0.107	0	0	102.7	5.09	4.26	123	true
J025958.0+003538	44.991679	0.594056	0.98	0.52	0.114	0	0	124.4	4.98	3.71	170.7	true
J025927.6+003626	44.865167	0.607478	5.11	4.9	0.118	0.76	0	67.5	6.17	5.37	9.8	true
J025937.4+003736	44.906067	0.626733	0.98	0.59	0.123	0	0	80.2	5.01	4.14	65.3	true
J025914.6+003558	44.810954	0.5996	0.82	0.6	0.113	1.5	0	91.8	5.61	4.59	93.9	true
J025859.6+003618	44.748554	0.605064	26.45	27.44	0.104	1.29	1	167.1	6.53	5.49	179.3	true
J025850.6+003543	44.710963	0.595297	0.94	0.5	0.098	0	0	101	4.58	4.06	144.3	true
J025919.6+004339	44.831883	0.7276	1.46	1.21	0.13	1.93	0	155.2	6.59	4.34	165.9	true
J025800.7+003404	44.502942	0.568042	19.75	21.4	0.103	2.17	1.09	38.2	6.67	5.61	7.6	true
J025743.2+004124	44.430108	0.690139	2.9	3.04	0.122	1.83	0	88.4	6.35	5.7	0.8	true
J025738.9+004133	44.412287	0.692617	0.98	0.95	0.126	3.8	0	102.6	6.67	5.04	110.3	true
J025830.9+004305	44.628813	0.718147	0.99	1.15	0.099	4.4	0	87.8	6.97	5.77	86.1	true
J025914.5+004411	44.810704	0.736603	0.94	0.44	0.128	0	0	108.5	4.54	3.57	165.9	true
J025904.7+004538	44.7698	0.760639	0.91	0.43	0.124	0	0	73.5	4.49	3.69	23.5	true
J025903.0+004628	44.762721	0.774667	2.2	1.53	0.125	0	0	82.5	5.4	4.44	2	true
J025859.0+004809	44.746004	0.802733	1.02	0.95	0.127	3.38	0	90.9	6.37	5.11	91.7	true
J025825.9+004510	44.607921	0.752889	6.12	6.42	0.104	2.04	0	142.2	6.61	5.48	170.5	true
J025813.9+004649	44.558217	0.780481	8.24	14.17	0.113	8.5	1.08	20.6	10.58	5.62	17.8	true
J025852.5+004831	44.718888	0.808783	1.46	1.29	0.124	1.08	0	9.1	6.48	4.73	3.7	true
J025824.2+004740	44.601029	0.794556	0.83	1.55	0.114	7.28	3.24	66.7	9.19	7	59.7	true
J030020.8+004442	45.087025	0.745225	3.75	4.22	0.135	2.53	1.3	106.9	6.58	5.91	170.8	true
J030007.6+004400	45.0319	0.733433	1.73	1.64	0.135	3.11	0	153.6	7.01	4.65	163.6	true
J030017.1+004721	45.071554	0.789311	1.18	0.72	0.134	0	0	101.9	5.15	4.15	117.2	true
J025932.7+004153	44.886542	0.698122	1.19	0.71	0.133	0	0	107.8	4.97	4.19	160.7	true
J025937.4+004304	44.906104	0.717908	0.96	1.31	0.135	6.89	0	56.9	8.99	5.27	51.1	true
J025935.6+004746	44.898433	0.796269	15.84	30.06	0.136	7.89	2.47	91.5	9.56	6.86	91.9	true
J025958.7+004630	44.994746	0.775078	1.58	2.98	0.134	10.84	0	150.1	12.48	5.22	152.4	true
J030045.2+004709	45.188596	0.785961	0.96	0.92	0.136	4.07	0	79.3	6.81	4.88	73.7	true
J030032.1+004800	45.1338	0.800228	0.94	1.42	0.136	7.1	0.7	175.1	9.56	5.45	176	true
J030054.4+005412	45.226875	0.903339	5.3	5.12	0.146	1.06	0	73.4	6.14	5.44	9.9	true
J030006.1+005233	45.025529	0.876036	1.82	3.65	0.135	8.18	3.24	118.3	9.96	6.95	123.9	true
J030007.1+005321	45.029796	0.889167	1.05	1.04	0.136	2.88	0	164.8	6.98	4.86	171.7	true
J030018.0+005511	45.075271	0.919892	17.72	38.69	0.138	9.61	2.46	98.5	11.04	6.84	99.8	true
J030040.2+005806	45.167696	0.968394	7.08	7.15	0.149	1.54	0	52.4	6.41	5.45	10	true
J030050.0+005955	45.208346	0.99875	67.92	73.62	0.149	2.26	1.15	179.6	6.79	5.52	179.9	true
J025911.2+004638	44.796787	0.777469	3.41	3.27	0.133	1.32	0	41.2	6.39	5.19	12.4	true
J025921.8+004949	44.840971	0.830358	1.2	1.24	0.139	4.46	0	113.3	7.18	4.99	122.6	true
J025901.0+004918	44.754504	0.821819	94.11	211.13	0.132	7.93	4.97	103.8	9.64	8.04	109.4	true
J025859.8+004928	44.74935	0.82465	34.49	128.2	0.132	16.55	3.83	109.6	17.45	7.36	110.5	true
J025900.2+004926	44.751071	0.823931	23.01	111.05	0.132	18.67	5.81	108.9	19.47	8.57	109.6	true
J025940.7+005548	44.919692	0.930239	2.97	7.68	0.138	10.82	3.95	60.1	12.22	7.3	57	true
J025901.0+005350	44.754458	0.897339	15.08	20.59	0.142	4.85	2.27	165.5	8	5.9	171.2	true
J025854.4+005329	44.727004	0.891644	1.04	3.17	0.14	9.31	7.59	39.5	11.13	9.51	29.3	true
J025904.6+005609	44.769254	0.935933	0.98	1.06	0.145	4.67	0	111.8	7.3	5.14	120.6	true
J025859.7+005631	44.748996	0.942075	1.12	1.7	0.143	5.45	2.34	90.5	7.67	6.81	91	true

End of preview. Expand in Data Studio

FIRST Radio Survey Catalog

Credit: NASA/JPL-Caltech

Part of a dataset collection on Hugging Face.

Dataset description

The Faint Images of the Radio Sky at Twenty-cm (FIRST) survey catalog, covering 10,575 square degrees at 1.4 GHz with 5 arcsecond resolution using the NRAO VLA.

The FIRST survey used the VLA in its B-configuration to produce a map of the radio sky at 1.4 GHz with ~5" resolution and a typical rms of 0.15 mJy/beam. The catalog includes source positions, peak and integrated flux densities, and fitted source sizes.

The FIRST survey was designed as a radio counterpart to the Palomar Observatory Sky Survey, targeting the north and south Galactic caps where optical and infrared surveys provide the richest multi-wavelength context. Its combination of sub-arcsecond positional accuracy and milliJansky sensitivity makes it ideally suited for identifying the radio counterparts of optically selected quasars, galaxies, and other extragalactic objects.

Unlike the broader but lower-resolution NVSS, FIRST resolves the internal structure of extended radio sources, revealing jets, lobes, and hotspots in radio galaxies. The survey's 5-arcsecond beam allows morphological classification of sources and reliable separation of core-dominated and lobe-dominated radio AGN.

Schema

Column	Type	Description	Sample	Null %
`source_name`	object	FIRST source identifier in the format "JHHMMSS.s+DDMMSS" derived from J2000 position	J030004.5+000946	0.0%
`ra_deg`	float64	ICRS J2000.0 right ascension in degrees (0-360); positional accuracy ~0.5 arcsec	45.01904166666666	0.0%
`dec_deg`	float64	ICRS J2000.0 declination in degrees; survey covers ~-10 to +62 deg	0.1630138888888888	0.0%
`peak_flux_mjy`	float64	Peak surface brightness at 1.4 GHz in mJy/beam; detection threshold ~0.75 mJy/beam	1.04	0.0%
`integrated_flux_mjy`	float64	Total integrated flux density from Gaussian fit in mJy; use for luminosity calculations	0.97	0.0%
`rms_mjy`	float64	Local rms noise at source position in mJy/beam; typically ~0.15 mJy/beam	0.104	0.0%
`major_axis_arcsec`	float64	Fitted (convolved) major-axis FWHM in arcsec; includes 5-arcsec beam	0.39	0.0%
`minor_axis_arcsec`	float64	Fitted (convolved) minor-axis FWHM in arcsec	0.0	0.0%
`position_angle_deg`	float64	Fitted position angle of major axis in degrees east from north (0-180)	119.1	0.0%
`deconv_major_arcsec`	float64	Deconvolved major axis in arcsec; 0 for unresolved point sources	6.17	0.0%
`deconv_minor_arcsec`	float64	Deconvolved minor axis in arcsec; 0 for unresolved sources	5.28	0.0%
`deconv_pa_deg`	float64	Deconvolved position angle in degrees; meaningful only when deconv_major_arcsec > 0	169.1	0.0%
`is_resolved`	bool	Derived: True if deconv_major_arcsec > 0 (source resolved above 5-arcsec beam)	True	0.0%

Quick stats

946,432 radio sources at 1.4 GHz
946,432 resolved sources (100.0% of catalog)
Median peak flux: 2.09 mJy/beam
Sky coverage: 10,575 square degrees (north + south Galactic caps)
Angular resolution: 5 arcsec (VLA B-configuration)

Usage

from datasets import load_dataset

ds = load_dataset("juliensimon/first-radio-catalog", split="train")
df = ds.to_pandas()

# Flux distribution (log scale — most sources are faint)
import matplotlib.pyplot as plt

fig, axes = plt.subplots(1, 2, figsize=(14, 5))

df["peak_flux_mjy"].clip(upper=100).hist(bins=200, log=True, ax=axes[0])
axes[0].set_xlabel("Peak flux (mJy/beam)")
axes[0].set_ylabel("Count")
axes[0].set_title("FIRST Source Flux Distribution")

# Sky coverage map
axes[1].scatter(df["ra_deg"], df["dec_deg"], s=0.01, alpha=0.1)
axes[1].set_xlabel("RA (deg)")
axes[1].set_ylabel("Dec (deg)")
axes[1].set_title("FIRST Survey Sky Coverage")
plt.tight_layout()
plt.show()

# Resolved vs unresolved statistics
print(f"Resolved:   {df['is_resolved'].sum():,}")
print(f"Unresolved: {(~df['is_resolved']).sum():,}")

Data source

https://vizier.cds.unistra.fr/viz-bin/VizieR-3?-source=VIII/92

Citation

@dataset{first_radio_catalog,
  title = {FIRST Radio Survey Catalog},
  author = {juliensimon},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/first-radio-catalog},
  publisher = {Hugging Face}
}