3C 346

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3C 346
SDSS image of 3C 346.jpg
SDSS image of 3C 346.
Observation data (J2000.0 epoch)
Constellation Hercules
Right ascension 16h 43m 48.59s
Declination +17° 15′ 49.46″
Redshift 0.163025
Heliocentric radial velocity 48,874 km/s
Distance 2.484 Gly (761.59 Mpc)
Apparent magnitude  (B)17.2
Characteristics
Type E;NLRG, Sy2
Notable features Radio galaxy
Other designations
4C 17.70, PKS J1643+1715, PGC 58857, DA 422, OS 170, NVSS J164348+171548

3C 346 is an elliptical galaxy located in the constellation Hercules. It is located nearly 2.5 billion light years away from Earth and classified a Seyfert galaxy and a compact steep-spectrum source (CSS), [1] although later studies confirm it as a Fanaroff-Riley class II source. [2]

Contents

Characteristics

3C 346 is classified a narrow-line radio galaxy. [3] It has a projected 0.5-3 keV luminosity of 1.4 x 1044 ergs s−1. The galaxy has a lack of X-ray emission given most of it originates from a cluster environment with a temperature of 1.9+1.3-0.7. [4] It is part of a double galaxy system where the object is found merging with a nearby companion galaxy. [5] 3C 346 also contains a jetted double radio source when observed in X-rays [6] and a bright hotspot region showing strong emission in ultraviolet, mainly caused by synchrotron radiation. [7]

The point-like emission of 3C 346 is found to be unabsorbed, measuring NH ≤ 2 x 1021 cm−2 with a spectral slope of αx = 0.69+0.16-0.14 and flux of 7.4 x 10−13erg cm−2 s−1 when observed by ROSAT PSPC observations. However, when observed by the Advanced Satellite for Cosmology and Astrophysics (ASCA) two years later, the emission presents a different spectral slope of αx = 0.73+0.17-0.23 with a lower flux level of 7.4 x 10−13 erg cm−2 s−1. [8]

The nucleus of 3C 346 is found to be luminous. [5] It contains a core component in which a one-sided radio jet is seen emerging with a projected extension of around ~ 2 arcsecs, hinting the jet's inclination to the line of sight has a tiny angle. [9] Reaching at high radio frequencies, the jet of 3C 346 contains individual bright knots located at different positions with increased distances from the core region. [4]

According to the jet being detected using Hubble Space Telescope optical polarimetry, Very Large Array polarimetry at 14.9 and 22.5 GHz and data from Chandra X-ray observatory, it shows similarities between optical and radio morphology. However the X-ray emission is found offset by 0.80 ± 0.17 kiloparsecs from both optical and radio peak positions. Based on polarization modeling, the jet of 3C 346 has a relativistic upstream flow of βu = 0.91+0.05-0.07 with an inclined shock front plane angle of η = 51° ± 11° and upstream flow angle of θ = 14+8−7 degrees. The deflection angle of the jet on the other hand, is 22°. [10]

There is also the presence of an extended structure with an extent of ~ 12" around the jet and its opposite side. When observed at 1.7 GHz, the region has two other components with an estimated separation of ~ 2".2. One of the components is found to be stronger and compacted, while the other component is merely a glowing knot inside the jet and mainly surrounded by extended emission. [11]

Related Research Articles

An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such excess, non-stellar emissions have been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy.

<span class="mw-page-title-main">BL Lacertae object</span> Type of active galactic nucleus

A BL Lacertae object or BL Lac object is a type of active galactic nucleus (AGN) or a galaxy with such an AGN, named after its prototype, BL Lacertae. In contrast to other types of active galactic nuclei, BL Lacs are characterized by rapid and large-amplitude flux variability and significant optical polarization. Because of these properties, the prototype of the class was originally thought to be a variable star. When compared to the more luminous active nuclei (quasars) with strong emission lines, BL Lac objects have spectra dominated by a relatively featureless non-thermal emission continuum over the entire electromagnetic range. This lack of spectral lines historically hindered identification of the nature and distance of such objects.

<span class="mw-page-title-main">Centaurus A</span> Radio galaxy in the constellation Centaurus

Centaurus A is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable debate in the literature regarding the galaxy's fundamental properties such as its Hubble type and distance. It is the closest radio galaxy to Earth, as well as the closest BL Lac object, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth-brightest in the sky, making it an ideal amateur astronomy target. It is only visible from the southern hemisphere and low northern latitudes.

<span class="mw-page-title-main">3C 305</span> Galaxy in the constellation Draco

3C 305, also known as IC 1065, is a lenticular galaxy located in the constellation Draco. The galaxy is located 577 million light-years away from Earth. It has an active galactic nucleus and is classified as a Seyfert 2 galaxy. This galaxy was discovered by American astronomer Lewis Swift on April 7, 1888.

<span class="mw-page-title-main">3C 66B</span> Elliptical radio galaxy in the constellation Andromeda

3C 66B is an elliptical Fanaroff and Riley class 1 radio galaxy located in the constellation Andromeda. With an estimated redshift of 0.021258, the galaxy is about 300 million light-years away.

<span class="mw-page-title-main">3C 79</span> Galaxy in the constellation Aries

3C 79 is a Seyfert Galaxy and a radio galaxy located in the constellation Aries. It is hosted by an elliptical galaxy described as elongated with a complex morphology.

<span class="mw-page-title-main">3C 285</span> Galaxy in constellation Canes Venatici

3C 285 is a radio galaxy located in the constellation Canes Venatici. It is located about 1 bilion light years away. It is a Fanaroff-Riley 2 radio galaxy and is hosted in a disturbed spiral galaxy.

<span class="mw-page-title-main">3C 438</span> Galaxy in the constellation Cygnus

3C 438 is a Seyfert galaxy and Fanaroff and Riley class II radio galaxy located in the constellation Cygnus. The radio galaxy has two lobes and there is a radio jet leading to the south lobe, which also has a prominent double hot spot. There is age variation across the lobes.

<span class="mw-page-title-main">NGC 3862</span> Galaxy in the constellation Leo

NGC 3862 is an elliptical galaxy located 300 million light-years away in the constellation Leo. Discovered by astronomer William Herschel on April 27, 1785, NGC 3862 is an outlying member of the Leo Cluster.

<span class="mw-page-title-main">NGC 708</span> Galaxy in the constellation Andromeda

NGC 708 is an elliptical galaxy located 240 million light-years away in the constellation Andromeda and was discovered by astronomer William Herschel on September 21, 1786. It is classified as a cD galaxy and is the brightest member of Abell 262. NGC 708 is a weak FR I radio galaxy and is also classified as a type 2 Seyfert galaxy.

<span class="mw-page-title-main">3C 120</span> Galaxy in the constellation Taurus

3C 120, also known as Markarian 1506, is an active galaxy located in the constellation of Taurus, at a distance of about 420 million light years. It has been categorised as a type I Seyfert galaxy and a broad-line radio galaxy. 3C 120 has been found to be a variable source in all wavelengths and hosts a superluminal jet.

<span class="mw-page-title-main">NGC 7720</span> Galaxy in the constellation Pegasus

NGC 7720 is an elliptical galaxy located in the constellation Pegasus. It is located at a distance of about 380 million light years from Earth, which, given its apparent dimensions, means that NGC 7720 is about 180,000 light years across. NGC 7720 is the main galaxy of Abell 2634 galaxy cluster and is a radio galaxy. It was discovered by William Herschel on September 10, 1784.

<span class="mw-page-title-main">Extended emission-line region</span> Interstellar clouds

An extended emission-line region (EELR) is a giant interstellar cloud ionized by the radiation of an active galactic nucleus (AGN) inside a galaxy or photons produced by the shocks associated with the radio jets. An EELR can appear as a resolved cloud in relative nearby galaxies and as narrow emission lines in more distant galaxies.

<span class="mw-page-title-main">NGC 5920</span> Lenticular galaxy located in constellation Serpens

NGC 5920 is a large lenticular galaxy located in the Serpens constellation. Discovered on March 30, 1887, by American astronomer Lewis Swift, NGC 5920 is 711 million light-years distant from planet Earth. It is a narrow-line radio galaxy and about 300,000 light-years in diameter.

<span class="mw-page-title-main">NGC 2484</span> Galaxy in the constellation Lynx

NGC 2484 is a large lenticular galaxy located in the Lynx constellation. It is situated 560 million light-years away from the Milky Way, which given by its apparent dimensions, means NGC 2484 is around 304,000 light-years across. It is classified a Fanaroff and Riley radio galaxy.

<span class="mw-page-title-main">3C 459</span> Radio galaxy in the constellation Pisces

3C 459 known as IRAS 23140+0348, is a radio galaxy located in the constellation Pisces. It is located 2.74 billion light years from Earth and is classified as a Seyfert 2 and LINER galaxy.

<span class="mw-page-title-main">3C 138</span> Quasar in the constellation Taurus

3C 138 is a quasar located in the constellation of Taurus. It has a redshift of (z) 0.76. The radio spectrum of this source appears both compact and steep, making it a compact steep-spectrum radio quasar. It is also one of the few 3C objects showing a defined and turn-over in its electromagnetic spectrum at low frequencies.

<span class="mw-page-title-main">3C 196.1</span> Radio galaxy in the constellation Hydra

3C 196.1 is a low-excitation radio galaxy located in the constellation of Hydra. It has a redshift of 0.198 and was first discovered as an astronomical radio source in 1965. This object resides as the brightest cluster galaxy (BCG) of a cool core galaxy cluster CIZA J0815.4-0308 located at the same redshift, with its source being best described as a HyMOR.

<span class="mw-page-title-main">3C 356</span> Radio galaxy in the constellation Draco

3C 356 is a distant radio galaxy located in the constellation of Draco, hosted by a merging pair of elliptical galaxies located at redshift (z) 1.079 with two radio cores having a separation gap of 5 arcseconds. It was first discovered as an astronomical radio source by P. Veron from a 3C revised catalogue in 1966 and such, shows an alignment effect at both wavelengths. The X-ray source luminosity for this galaxy is estimated to be 2.5 x 1044 erg s−1.

<span class="mw-page-title-main">3C 382</span> Broad-line radio galaxy located in the constellation Lyra

3C 382 is a nearby broad-line radio galaxy located in the constellation of Lyra, located at a redshift of (z) 0.058. First discovered as an astronomical radio source in 1963 and identified with its optical counterpart in 1973, the galaxy is classified as a Fanaroff-Riley class II radio galaxy. Its X-ray luminosity is estimated to be 7×1044 erg/s in the 0.2–2.4 keV band.

References

  1. ↑ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-10-05.
  2. ↑ Dey, Arjun; van Breugel, Wil J. M. (1994-06-01). "Blue Optical Continuum Associated With a Radio Knot in 3C346". The Astronomical Journal. 107: 1977. Bibcode:1994AJ....107.1977D. doi:10.1086/117009. ISSN   0004-6256.
  3. ↑ Trussoni, E.; Capetti, A.; Celotti, A.; Chiaberge, M. (May 2000). "X-ray observations of 3C 66B and 3C 346". Memorie della Società Astronomica Italiana. 72 (1): 111–113. Bibcode:2001MmSAI..72..111T. ISSN   0037-8720.
  4. 1 2 Worrall, D. M.; Birkinshaw, M. (2001-04-10). "The X-Ray Emission of 3C 346 and Its Environment". The Astrophysical Journal. 551 (1): 178–185. arXiv: astro-ph/0012350 . Bibcode:2001ApJ...551..178W. doi:10.1086/320068. ISSN   0004-637X.
  5. 1 2 P. Madrid, Juan; Chiaberge, Marco; Floyd, David; B. Sparks, William; Macchetto, Duccio; K. Miley, George; Axon, David; Capetti, Alessandro; P. O'Dea, Christopher; Baum, Stefi (June 2006). "Hubble Space Telescope Near-Infrared Snapshot Survey of 3CR Radio Source Counterparts at Low Redshift1". The Astrophysical Journal Supplement Series. 164 (2): 307–333. arXiv: astro-ph/0603239 . Bibcode:2006ApJS..164..307M. doi:10.1086/504480.
  6. ↑ Hardcastle, M. J.; Worrall, D. M. (1999-11-11). "ROSAT X-ray observations of 3CRR radio sources". Monthly Notices of the Royal Astronomical Society. 309 (4): 969–990. arXiv: astro-ph/9907034 . Bibcode:1999MNRAS.309..969H. doi: 10.1046/j.1365-8711.1999.02945.x . ISSN   0035-8711.
  7. ↑ de Vries, W. H.; O'Dea, C. P.; Baum, S. A.; Sparks, W. B.; Biretta, J.; de Koff, S.; Golombek, D.; Lehnert, M. D.; Macchetto, F.; McCarthy, P.; Miley, G. K. (June 1997). "Hubble Space Telescope|Imaging of Compact Steep Spectrum Radio Sources". The Astrophysical Journal Supplement Series. 110 (2): 191–211. Bibcode:1997ApJS..110..191D. doi:10.1086/313001. ISSN   0067-0049.
  8. ↑ Trussoni, E.; Capetti, A.; Celotti, A.; Chiaberge, M.; Feretti, L. (March 2003). "A multi-wavelength test of the FR I–BL Lac unifying model" (PDF). Astronomy & Astrophysics. 403 (3): 889–899. arXiv: astro-ph/0304018 . Bibcode:2003A&A...403..889T. doi:10.1051/0004-6361:20030417.
  9. ↑ Gupta, Neeraj; Salter, C. J.; Saikia, D. J.; Ghosh, T.; Jeyakumar, S. (2006-11-13). "Probing radio source environments via H i and OH absorption". Monthly Notices of the Royal Astronomical Society. 373 (3): 972–992. arXiv: astro-ph/0605423 . Bibcode:2006MNRAS.373..972G. doi: 10.1111/j.1365-2966.2006.11064.x . ISSN   0035-8711.
  10. ↑ Dulwich, F.; Worrall, D. M.; Birkinshaw, M.; Padgett, C. A.; Perlman, E. S. (2009-09-21). "The magnetic field and geometry of the oblique shock in the jet of 3C 346". Monthly Notices of the Royal Astronomical Society. 398 (3): 1207–1216. arXiv: 0907.3739 . Bibcode:2009MNRAS.398.1207D. doi: 10.1111/j.1365-2966.2009.15211.x . ISSN   0035-8711.
  11. ↑ Cotton, W.D.; Feretti, L.; Giovannini, G.; Venturi, T.; Lara, L.; Marcaide, J.; Wherle, A.E. (October 1995). "VLBI Observations of a Complete Sample of Radio Galaxies. V. 3C 346 and 4C 31.04: Two Unusual Compact Steep Spectrum Sources". The Astrophysical Journal. 452: 605–612. arXiv: astro-ph/9506038 . Bibcode:1995ApJ...452..605C. doi:10.1086/176333.
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