4C +26.42 is an elliptical galaxy located in the constellation of Boötes. It has a redshift of 0.063, estimating the galaxy to be located 863 million light-years from Earth.[1] It has an active galactic nucleus and is the brightest cluster galaxy (BCG) in Abell 1795,[2] an X-ray luminous rich cluster (LX 1045 ergs s-1), with an estimated cooling-flow rate of 300 M yr-1.[3]

4C +26.42
4C +26.42, as seen by DESI Legacy Surveys
Observation data (J2000 epoch)
ConstellationBoötes
Right ascension13h 48m 52.54s
Declination+26° 35′ 33.65″
Redshift0.063309
Heliocentric radial velocity18,980 km/s
Distance863 Mly (264.6 Mpc)
Group or clusterAbell 1795
Apparent magnitude (V)0.037
Apparent magnitude (B)0.048
Surface brightness15.2
Characteristics
TypecD; S0?;LINER S3
Apparent size (V)1.0' x 1.0'
Notable featuresRadio galaxy, brightest cluster galaxy
Other designations
CGCG 162-010, MCG +05-33-005, PGC 49005, 7C 1346+2650 PKS 1346+26, TXS 1346+268, NVSS J134852+263533

Properties

edit

4C +26.42 is one of the powerful radio galaxies inhabiting the center of the cluster.[4] Radio-loud,[5] low-luminous[6] and classified as a Fanaroff-Riley class I, the galaxy contains a strong double-lobed radio source,[7] that stretches ≈10 kpc on both sides of the nucleus region measuring P1.4 1025 W Hz-1[8] and found occupying inside the cluster flow.[9] It has a radial velocity of 365 km s-1,[10] with a complex core structure,[11] and pole-on dispersion in diameter, indicating a marginal intrinsic dispersion.[12] Furthermore, it is a LINEAR galaxy, with an emission spectrum characterized by broad weak ion atoms.[13]

The galaxy is known have a pair of filaments, coiled together. Known as the "SE Filament", they are estimated to have a distance of ~ 42″ and 35″ respectively but have unresolved widths in Hα (< 0.7″ ~ 1 kpc) with thin-looking appearances, reminding of magnetic field lines.[14]

An structure has been discovered inside the envelope of 4C +26.42. Traced from a previous merger with another giant subcluster galaxy,[15] the structure has a measurement of 400 kpc from the center which protrudes towards the north–south direction. When reached at the largest radius, a low-surface brightness region is found, with a slight angle pointing towards east direction. According to researchers, the total I-band magnitude and envelope of the galaxy is -26.6, making 4C +26.42 among the brightest galaxies known.[16]

Nebula line emission

edit

4C +26.42 contains a nebular line emission found coruscating. With a luminosity range of L(Hα) ≈ 1042 ergs s-1, within 20 kpc from the central galaxy, the line emission is embedded inside a filament extending towards the southern nucleus region by 80 kpc.[17] An excessive blue light is also found as well, which is probably emitted out from both young stars in globular clusters[18] and massive star populations located inside the galaxy similar to Hydra A.[19]

Molecular outflows by radio bubbles

edit

4C +26.42 is known to manifest robust molecular 109 M⊙ gas flows, with molecular gas positioned in a pair of filaments. With an estimated length of ~ 7 kpc, north and south from the nucleus, the filaments are jutted around the outer edges of two inflated radio bubbles, caused by evaporation of plasma through heated radio jets launched by the galaxy.[20]

Results shows North filament is found flat and increased velocity gradient that goes from the systemic velocity at the nucleus to a maximum velocity of -370 km s-1. As for the South filament, it shows the opposite by having a shallow velocity gradient, practically collapsed through starbursts. Through comparing both filaments together, they show a close bond specifying these filaments are indeed gas flows caused by the expansion of radio bubbles. Researchers concluded the total amount of molecular gas mass is 3.2 ± 0.2 × 109 M⊙.[21]

Estimated star formation

edit

The star formation in 4C +26.42 are shown to vary, based on different observations. Several studies shows, the estimated star formation rate is said to be smaller than 1–20 M yr−1 based on different data and methods.[22][23] Based on ultraviolet imaging, it is said to betwixt of 5 and 20 M yr−1. Deducing the initial mass function (IMF) as top-heavy with a slope of 3.3 yields, researchers suggested the star formation in 4C +26.42 is extremely high, reaching star formation rates of 581 and 758 M yr−1.[24]

It was not until then researchers decided to calculated the actual star formation in 4C +26.42. Detecting Lyman-alpha that is emitted from the galaxy,[25] they found it has a significant number of O-type stars within luminosity ranges of 1500 Å, L1500 = 1.9 × 1042 ergs s-1. Applying new methods like Galactic extinction law,[26] extinction value (EB-V = 0.14)[27] and foreground screen dust modes, they predicted the increasement of O-type stars is 5.3 x 104. Accurately, the O-type stars is 2.4 × 104 based on a modern spectroscopy method,[28] indicating the actual star formation rate is only within the compass of 8-23 M yr-1. Finally researchers used a star formation model corresponding to far-ultraviolet colors whom they found the star production rate in 4C +26.42 is 5-10 M yr-1 over the past 5 billion years.[29]

Radio morphology

edit

According to Very Long Baseline Array observations at 1.6, 5, 8.4 and 22 GHz, 4C +26.42 has a two-sided source, with a geometrical Z-structure located from the core region by ~5 mas.[30] The radio morphology is found on small-scale with core-power 5 GHz Log Pcore, 5GHz = 23.70 W/Hz and radio power results at 0.4 GHz Log Ptot, 0.4 GHz.[31]

Faraday rotational measure

edit

The faraday rotational measure in 4C +26.42 is extortionate. Exceeding 2000 rad m-2 when observed in high resolution (0.6 arcsec) VLA images, the radio source is found polarized by 10% to 30%.[32] The magnitude and the scale comparable with a boiling (108) and thick (0.03 cm-3) X-ray emitting gas. Based on the degree of ordering, the magnetic field field is within the ranges of 20 and 100 μG.[30]

References

edit
  1. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-06-28.
  2. ^ Ehlert, S.; McDonald, M.; Miller, E. D.; David, L. P.; Bautz, M. W. (2015-01-28). "A very deep Chandra observation of Abell 1795: The Cold Front and Cooling Wake". The Astrophysical Journal. 799 (2): 174. arXiv:1406.4352. doi:10.1088/0004-637X/799/2/174. ISSN 1538-4357.
  3. ^ Edge, A. C.; Stewart, G. C.; Fabian, A. C. (1992-09-01). "Properties of cooling flows in a flux-limited sample of clusters of galaxies". Monthly Notices of the Royal Astronomical Society. 258: 177–188. Bibcode:1992MNRAS.258..177E. doi:10.1093/mnras/258.1.177. ISSN 0035-8711.
  4. ^ Prestage, Richard M.; Peacock, John A. (1988-01-01). "The cluster environments of powerful radio galaxies". Monthly Notices of the Royal Astronomical Society. 230: 131–160. Bibcode:1988MNRAS.230..131P. doi:10.1093/mnras/230.1.131. ISSN 0035-8711.
  5. ^ Burns, Jack O. (1990-01-01). "The Radio Properties of cD Galaxies in Abell Clusters. I. an X-ray Selected Sample". The Astronomical Journal. 99: 14. Bibcode:1990AJ.....99...14B. doi:10.1086/115307. ISSN 0004-6256.
  6. ^ Morganti, R.; Fanti, R.; Gioia, I. M.; Harris, D. E.; Parma, P.; de Ruiter, H. (1988-01-01). "Low luminosity radio galaxies : effects of gaseous environment". Astronomy and Astrophysics. 189: 11–26. Bibcode:1988A&A...189...11M. ISSN 0004-6361.
  7. ^ Roland, J.; Véron, P.; Pauliny-Toth, I. I. K.; Preuss, E.; Witzel, A. (1976-07-01). "Radio sources and clusters of galaxies". Astronomy and Astrophysics. 50: 165–170. Bibcode:1976A&A....50..165R. ISSN 0004-6361.
  8. ^ van Breugel, W.; Heckman, T.; Miley, G. (1984-01-01). "Optical line emission associated with the radio galaxy 4C 26.42 in the cluster of galaxies Abell 1795". The Astrophysical Journal. 276: 79–91. Bibcode:1984ApJ...276...79V. doi:10.1086/161594. ISSN 0004-637X.
  9. ^ McKee, J. D.; Mushotzky, R. F.; Boldt, E. A.; Holt, S. S.; Marshall, F. E.; Pravdo, S. H.; Serlemitsos, P. J. (1980-12-01). "The HEAO A-2 survey of Abell clusters and the X-ray luminosity function". The Astrophysical Journal. 242: 843–856. Bibcode:1980ApJ...242..843M. doi:10.1086/158518. ISSN 0004-637X.
  10. ^ Hill, John M.; Hintzen, Paul; Oegerle, W. R.; Romanishin, W.; Lesser, M. P.; Eisenhamer, J. D.; Batuski, D. J. (1988-09-01). "Peculiar Velocities of cD Galaxies: MX Spectroscopy of Abell 1795". The Astrophysical Journal. 332: L23. Bibcode:1988ApJ...332L..23H. doi:10.1086/185258. ISSN 0004-637X.
  11. ^ Liuzzo, E.; Giovannini, G.; Giroletti, M. (2011-03-02), Nuclear properties of Brightest Cluster Galaxies: results and new observations for two peculiar cases, arXiv:1103.0450
  12. ^ Ftaclas, C.; Struble, M. F. (1983-11-01). "The intrinsic shape of cD galaxies". The Astrophysical Journal. 274: 521–528. Bibcode:1983ApJ...274..521F. doi:10.1086/161465. ISSN 0004-637X.
  13. ^ Véron-Cetty, M. -P.; Véron, P. (2006-08-01). "A catalogue of quasars and active nuclei: 12th edition". Astronomy and Astrophysics. 455 (2): 773–777. Bibcode:2006A&A...455..773V. doi:10.1051/0004-6361:20065177. ISSN 0004-6361.
  14. ^ McDonald, Michael; Veilleux, Sylvain (2009-09-16). "MMTF-Hα AND HST -FUV IMAGING OF THE FILAMENTARY COMPLEX IN ABELL 1795". The Astrophysical Journal. 703 (2): L172–L177. arXiv:0909.1554. Bibcode:2009ApJ...703L.172M. doi:10.1088/0004-637x/703/2/l172. ISSN 0004-637X.
  15. ^ Schombert, James M. (1987-08-01). "The Structure of Brightest Cluster Members. II. Mergers". The Astrophysical Journal Supplement Series. 64: 643. Bibcode:1987ApJS...64..643S. doi:10.1086/191212. ISSN 0067-0049.
  16. ^ Johnstone, R. M.; Naylor, T.; Fabian, A. C. (1991-02-01). "Discovery of structure in the envelope of the cD galaxy in the cluster Abell 1795". Monthly Notices of the Royal Astronomical Society. 248: 18P–20P. Bibcode:1991MNRAS.248P..18J. doi:10.1093/mnras/248.1.18P. ISSN 0035-8711.
  17. ^ Cowie, L. L.; Hu, E. M.; Jenkins, E. B.; York, D. G. (1983-09-01). "Two-dimensional spectrophotometry of the cores of X-ray luminous clusters". The Astrophysical Journal. 272: 29–47. Bibcode:1983ApJ...272...29C. doi:10.1086/161259. ISSN 0004-637X.
  18. ^ Holtzman, J. A.; Watson, A. M.; Mould, J. R.; Gallagher III, J. S.; Ballester, G. E.; Burrows, C. J.; Clarke, J. T.; Crisp, D.; Evans, R. W.; Griffiths, R. E.; Hester, J. J.; Hoessel, J. G.; Scowen, P. A.; Stapelfeldt, K. R.; Trauger, J. T. (1996-08-01). "Star Clusters in Interacting and Cooling Flow Galaxies". The Astronomical Journal. 112: 416. Bibcode:1996AJ....112..416H. doi:10.1086/118025. ISSN 0004-6256.
  19. ^ McNamara, B. R.; Wise, M.; Nulsen, P. E. J.; David, L. P.; Sarazin, C. L.; Bautz, M.; Markevitch, M.; Vikhlinin, A.; Forman, W. R.; Jones, C.; Harris, D. E. (2000-05-10). "[ITAL]Chandra[/ITAL] X-Ray Observations of the Hydra A Cluster: An Interaction between the Radio Source and the X-Ray–emitting Gas". The Astrophysical Journal. 534 (2): L135–L138. doi:10.1086/312662. ISSN 0004-637X. PMID 10813666.
  20. ^ Fabian, A. C.; Sanders, J. S.; Ettori, S.; Taylor, G. B.; Allen, S. W.; Crawford, C. S.; Iwasawa, K.; Johnstone, R. M. (2001-02-01). "Chandra imaging of the X-ray core of Abell 1795". Monthly Notices of the Royal Astronomical Society. 321 (2): L33–L36. arXiv:astro-ph/0011547. Bibcode:2001MNRAS.321L..33F. doi:10.1046/j.1365-8711.2001.04243.x. ISSN 0035-8711.
  21. ^ Russell, H. R.; McNamara, B. R.; Fabian, A. C.; Nulsen, P. E. J.; Combes, F.; Edge, A. C.; Hogan, M. T.; McDonald, M.; Salomé, P.; Tremblay, G.; Vantyghem, A. N. (2017-12-01). "Close entrainment of massive molecular gas flows by radio bubbles in the central galaxy of Abell 1795". Monthly Notices of the Royal Astronomical Society. 472 (4): 4024–4037. arXiv:1708.08935. Bibcode:2017MNRAS.472.4024R. doi:10.1093/mnras/stx2255. ISSN 0035-8711.
  22. ^ Donahue, Megan; de Messières, Geneviève E.; O'Connell, Robert W.; Voit, G. Mark; Hoffer, Aaron; McNamara, Brian R.; Nulsen, Paul E. J. (2011-05-01). "Polycyclic Aromatic Hydrocarbons, Ionized Gas, and Molecular Hydrogen in Brightest Cluster Galaxies of Cool-core Clusters of Galaxies". The Astrophysical Journal. 732 (1): 40. arXiv:1103.1410. Bibcode:2011ApJ...732...40D. doi:10.1088/0004-637X/732/1/40. ISSN 0004-637X.
  23. ^ Hicks, A. K.; Mushotzky, R. (2005-12-01). "Star Formation Rates in Cooling Flow Clusters: A UV Pilot Study with Archival XMM-Newton Optical Monitor Data". The Astrophysical Journal. 635 (1): L9–L12. arXiv:astro-ph/0508143. Bibcode:2005ApJ...635L...9H. doi:10.1086/499123. ISSN 0004-637X.
  24. ^ Tamhane, Prathamesh D; McNamara, Brian R; Russell, Helen R; Combes, Francoise; Qiu, Yu; Edge, Alastair C; Maiolino, Roberto; Fabian, Andrew C; Nulsen, Paul E J; Johnstone, R; Carniani, Stefano (2022-12-29). "Radio jet–ISM interaction and positive radio-mechanical feedback in Abell 1795". Monthly Notices of the Royal Astronomical Society. 519 (3): 3338–3356. doi:10.1093/mnras/stac3803. ISSN 0035-8711.
  25. ^ Norgaard-Nielsen, H. U.; Jorgensen, H. E.; Hansen, L. (1984-06-01). "Detection of diffuse LY alpha emission from cD galaxy in Abell 1795". Astronomy and Astrophysics. 135: L3–L6. Bibcode:1984A&A...135L...3N. ISSN 0004-6361.
  26. ^ Savage, B. D.; Mathis, J. S. (1979-01-01). "Observed properties of interstellar dust". Annual Review of Astronomy and Astrophysics. 17: 73–111. Bibcode:1979ARA&A..17...73S. doi:10.1146/annurev.aa.17.090179.000445. ISSN 0066-4146.
  27. ^ Hu, Esther M. (1992-06-01). "LY alpha Emission from Cooling Flows and Measures of the Dust Content of Rich Clusters of Galaxies". The Astrophysical Journal. 391: 608. Bibcode:1992ApJ...391..608H. doi:10.1086/171374. ISSN 0004-637X.
  28. ^ Allen, S. W. (1995-10-01). "Starbursts in cooling flows: blue continua and emission-line nebulae in central cluster galaxies". Monthly Notices of the Royal Astronomical Society. 276 (3): 947–960. Bibcode:1995MNRAS.276..947A. doi:10.1093/mnras/276.3.947. ISSN 0035-8711.
  29. ^ Smith, Eric P.; Bohlin, Ralph C.; Bothun, G. D.; O'Connell, Robert W.; Roberts, Morton S.; Neff, Susan G.; Smith, Andrew M.; Stecher, Theodore P. (April 1997). "Ultraviolet Imaging Observations of the cD Galaxy in Abell 1795: Further Evidence for Massive Star Formation in a Cooling Flow". The Astrophysical Journal. 478 (2): 516–521. arXiv:astro-ph/9611024. Bibcode:1997ApJ...478..516S. doi:10.1086/303819. ISSN 0004-637X.
  30. ^ a b Liuzzo, E.; Taylor, G. B.; Giovannini, G.; Giroletti, M. (2009-05-19). "The parsec-scale properties of the radio galaxy 4C 26.42 in the dense cooling core cluster A1795". Astronomy & Astrophysics. 501 (3): 933–940. arXiv:0905.3453. Bibcode:2009A&A...501..933L. doi:10.1051/0004-6361/200911964. ISSN 0004-6361.
  31. ^ Giovannini, G.; Taylor, G. B.; Feretti, L.; Cotton, W. D.; Lara, L.; Venturi, T. (2005-01-01). "The Bologna Complete Sample of Nearby Radio Sources". The Astrophysical Journal. 618 (2): 635–648. arXiv:astro-ph/0409624. Bibcode:2005ApJ...618..635G. doi:10.1086/426106. ISSN 0004-637X.
  32. ^ Ge, Jing P.; Owen, Frazer N. (1993-03-01). "Faraday Rotation in Cooling Flow Clusters of Galaxies. I. Radio and X-Ray Observations of Abell 1795". The Astronomical Journal. 105: 778. Bibcode:1993AJ....105..778G. doi:10.1086/116471. ISSN 0004-6256.