HCG 3
| HCG 3 | |
|---|---|
 HCG 3 seen by Legacy Surveys Dr10 | |
| Observation data (Epoch J2000) | |
| Constellation | Cetus |
| Right ascension | 00h 34m 28.8000s |
| Declination | −07° 34′ 58.800″ |
| Number of galaxies | 4 |
| Velocity dispersion | 251.2 km/s |
| Redshift | 0.026321 |
| Distance | 363.4 Mly (111.43 Mpc) |
| Other designations | |
| [DZ2015] 471 | |
HCG 3 is a compact group of galaxies from the Hickson Compact Group catalog. It is located in the Constellation Cetus, less than 1 degree north of NGC 157 and is 111.43 ± 7.81 Mega Parsecs away. Hickson Compact Group 3, along with 99 others, was identified by Paul Hickson in 1982.[1] HCG 3 has a radial velocity dispersion of 251 km/s and the crossing time is H₀tc = 0.023.[2]
Properties
[edit]Far-Infrared Studies by using the Infrared Astronomical Satellite (IRAS) shows that only HCG 3C emits a strong infrared signal, indicating a high amount of star formation and stellar nurseries. Far-infrared astronomy detects thermal radiation of interstellar dust contained in molecular clouds and nebulas, making it a reliable source to detect for massive amount star formation. Far-Infrared Luminosity of HCG 3C is 10.433L☉, but for HCG 3A, 3B and 3D, their emission is weak or not detected by the satellite.[3]
B_T is the total brightness of the specific galaxy seen through a blue filter. HCG 3A is the brightest of the four, and HCG 3C is the dimmest of the four as shown in the table. B-R is equivalent to Blue minus Red, which is used to study star formation in the targeted galaxy. HCG 3C has the lowest B-R, indicating a large amount of molecular cloud formation, while HCG 3B has the highest B-R, representing a high amount of old stellar population.
Members
[edit]HCG 3[4] consists of 4 member galaxies. Their details are written below.
| HCG | Galaxy | Type | Ra | Dec | Diameter (") | Estimated Distance (Megaparsec) | Velocity (km/s)[5] | B-R[6] | B_T[6] |
|---|---|---|---|---|---|---|---|---|---|
| 3A | MCG -01-02-032[7] | Sc | 00h 34m 13.1990s | −07° 33′ 53.554″ | 67.50 | 102.75 | 7302 | 1.4100 | 15.36 |
| 3B | PGC 2064[8] | SB0a | 00h 34m 25.1139s | −07° 35′ 58.212″ | 56.70 | 110.98 | 7860 | 1.7100 | 15.64 |
| 3C | PGC 2059[9] | Sd? | 00h 34m 20.0199s | −07° 36′ 00.926″ | 25.40 | 165.33 | 11545 | 1.3700 | 16.54 |
| 3D | PGC 2043[10] | S0 | 00h 34m 09.8359s | −07° 36′ 08.595″ | 44.40 | 110.15 | 7804 | 1.6900 | 15.91 |
References
[edit]- ↑ Hickson, P. (1982). "Systematic properties of compact groups of galaxies". Astrophysical Journal. 255: 382. Bibcode:1982ApJ...255..382H. doi:10.1086/159838.
- ↑ Hickson, P. (1992). "Dynamical Properties of Compact Groups of Galaxies". Astrophysical Journal. 399: 353. Bibcode:1992ApJ...399..353H. doi:10.1086/171932.
- ↑ Verdes-Montenegro, L. (1998). "Effects of Interaction-Induced Activities in Hickson Compact Groups: CO and Far-Infrared Study". Astrophysical Journal. 497: 89. Bibcode:1998ApJ...497...89V. doi:10.1086/305456.
- ↑ "NED results for HCG 003". NASA/IPAC Extragalactic Database. Retrieved 2026-05-17.
- ↑ Hickson, P. (1993). Atlas of Compact Groups of Galaxies. NASA Astrophysics Data System. p. 12. Bibcode:1993ApL&C..29....1H.
- 1 2 Hickson, P.; Kindl, E.; Auman, J. R. (1989). "A photometric catalog of compact groups of galaxies". The Astrophysical Journal Supplement Series. 70: 687. Bibcode:1989ApJS...70..687H. doi:10.1086/191354.
- ↑ "NED results for MCG -01-02-032". NASA/IPAC Extragalactic Database. Retrieved 2026-05-17.
- ↑ "NED results for WISEA J003425.11-073558.2". NASA/IPAC Extragalactic Database. Retrieved 2026-05-17.
- ↑ "NED results for WISEA J003420.01-073600.9". NASA/IPAC Extragalactic Database. Retrieved 2026-05-17.
- ↑ "NED results for WISEA J003409.83-073608.5". NASA/IPAC Extragalactic Database. Retrieved 2026-05-17.
