Langbahn Team – Weltmeisterschaft

PKS 1345+125

PKS 1345+125
PKS 1345+125 captured by SDSS
Observation data (J2000.0 epoch)
ConstellationBoötes
Right ascension13h 47m 33.36s
Declination+12d 17m 24.24s
Redshift0.121740
Heliocentric radial velocity36,497 km/s
Distance1.699 Gly (521 Mpc)
Apparent magnitude (V)0.092
Apparent magnitude (B)0.121
Surface brightness16.6
Characteristics
TypeS0; Double nuc. Sy2
Size0.44' x 0.29'
Notable featuresLuminous infrared galaxy, galaxy merger
Other designations
4C +12.50, IRAS 13451+1232, PGC 48898, OP +175, NVSS J134733+121724, FIRST J134733.3+121724, GB6 J1347+1217, TXS 1345+125, CoNFIG 177, MRC 1345+125, PKS B1345+125

PKS 1345+125 known as PKS 1345+12 and 4C +12.50, is an ultraluminous infrared galaxy (ULIG)[1][2] with an active galactic nucleus, located in the constellation Boötes. With a redshift of 0.121740, the galaxy is located 1.7 billion light-years from Earth.[3]

Characteristics

A merger of two gas-rich galaxies consisting of one elliptical and one spiral,[4][5] PKS 1345+125 is the powerful radio galaxy[6] ever detected in CO (1 → 0) to date with a radio luminosity of P408 MHz = 2.4 × 1026 W Hz−1.[7] It presents a compact astrophysical jet[8] that is 0.1" ~200 pc wide, a high molecular gas mass measuring 4.4 × 1010 M[9] and contains a gigahertz peaked-spectrum radio source (GPS)[10] within the extent of its narrow-line region (<~1 kpc).[11] Through study of its radio structure, PKS 1345+125 shows a misaligned radio feature of ~49^deg^.[5]

The galaxy is part of a family of "warm" (f25 m/f60 m  0.2, that is similar to the colors of Seyfert galaxies.[12] Such infrared galaxies like PKS 1345+125, are in a transition state between the "cold" (f25 m/f60 m < 0.2) ULIG phenomenon, where active star formation are occurring,[13] with their accretion disks forming around the black hole and in optical quasar phases.[14] This shows molecular gas is used as a fuel source to power its active nucleus.[15]

According to researchers who studied PKS 1345+125, the galaxy contains ratios of narrow optical emission lines; this indicates Seyfert 2 activity.[16][17] The two nuclei in the galaxy have a projected separation of ≈ 2″ ~ 4 kpc and are surrounded by an extended asymmetrical galactic halo that is detected in both infrared and optical images.[18] These signs shows both black holes are on a verge of merging.[19] Furthermore, a powerful obscured quasar nucleus at wavelengths, is detected with a broad (△vFWHM ~ 2600 km s−1) Pa emission, through recent near-infrared spectroscopic observations.[20][21]

In addition to narrow optical emission lines, the column densities of N(H I) = 2-7 x 10^18^T_s_ atoms cm^-2^ in PKS 134+125 is found to have line extent of almost 1000 km s^-1^, indicating large amounts of cold gas present, which is responsible for bending the radio jet. Compared to Arp 220, the infrared and interstellar gas properties are higher in PKS 1345+125.[22]

Observation of PKS 1345+125

Researchers who studied PKS 1345+125 have suggested the radio source is a prime candidate for the link between young radio galaxies as well as ultraluminous infrared galaxies. From a VLBI study on neutral hydrogen inside nuclear regions of this object, they showed most gas detected close to the systemic velocity, are found to be associated with an off-nuclear cloud ( ~ 50 to 100 pc from its radio core. Not to mention, the gas has a column density of 1022 Tspin/100 k cm−2 with a H1 mass of 105 to 106 M○.[23]

From the results, researchers hinted the interstellar cloud in PKS 1345+125 has presence of rich and clumpy interstellar medium located inside the centre. Such traces are left over from the merger event that triggered the activity in PKS 1345+125 and growth of the radio source, influenced the medium. The proximity of the gas cloud at the edge of the northern radio lobe according to them, is suggested to be interacting with the radio jet causing it to be bended. The velocity profile of the gas on the other hand, is relatively broad ( ~ 150 km s−1), which researchers interpret this as a sign of kinematical evidence for interaction of the radio plasma with the cloud.[23]

Through imaging with Hubble Space Telescope and long-slit spectra by the William Herschel Telescope at La Plama in Spain, researchers detected young stellar populations in PKS 1345+125 with bright blue knots indicating super star clusters. These star clusters are found to have ages of tSSC < 6Myr with reddenings 0.2 < E(B - V) < 0.5 and solar masses of 106 < MYSPSSC < 107Msolar. The young stellar populations meanwhile, are in diffuse light that are stretched across the full extent of the halo with relatively young age of ~5 Myr. Researchers also studied the locations of super star clusters. The long-slit spectra shows they are moving at 450 km−1 in respect to local ambient gas; this is proven they either formed through fast moving gas streams infalling back to the galaxy's nuclear regions or by jet-induced star formation.[24]

Radio source

The radio source in PKS 1345+125 is found to be a compact symmetric source[25] according to researchers who observed it in optical and infra-red images. An extended line emission around ~20kpc, is said to be consistent with the asymmetric halo of diffuse emission. In its nucleus, 3 Gaussian components (narrow, intermediate and broad) are located. The broadest component (FWHM ~2000 km/s) is blue shifted by ~2000 km/s with respect to the galaxy halo and HI absorption, which they interpret it as material outflow.[26]

Researchers further found evidence for high reddening and measure E(B-V)>0.92 for the broadest component in PKS 1345+125. From value of [S II]6716,6731, the electron densities of n_e<150 cm^{-3}, n_{e}>5300 cm^{-3} and n_{e}>4200 cm^{-3} are then estimated for all regions. According to them, total mass of line emitting gas is calculated as M_{gas}<10^6 solar masses. This proves PKS 1345+125 is a young radio source with nuclear regions covered by gas and dust cocoons.[26][27]

Outflow of PKS 1345+125

The total kinetic outflow in PKS 1345+125 is 8 M_sun yr^-1, thanks to researchers who measured electron densities of Ne=2.94x10^3 cm^-3, Ne=1.47x10^4 cm^-3 and Ne=3.16x10^5 cm^-3 for the narrow, broad and very broad region components. But only a small fraction (0.13% of Lbol) of the accretion power available are driving the warm outflows. This is significantly less compared to accretion power required by majority of quasar feedback models (~5-10\% of Lbol). Although the model predicted the gas is removed through active galactic nucleus outflows from the host galaxy, the warm outflow is unable to do so. Possibly most of the outflow is either trapped by a dusty cocoon or in hotter or colder phrases. This result is not only important for studying young radio sources but for active galactic nuclei.[28]

References

  1. ^ Kim, Dong-Chan (1995-01-01). The IRAS 1 JY Survey of Ultraluminous Infrared Galaxies (Thesis). Bibcode:1995PhDT........11K.
  2. ^ Murphy, T. W., Jr.; Armus, L.; Matthews, K.; Soifer, B. T.; Mazzarella, J. M.; Shupe, D. L.; Strauss, M. A.; Neugebauer, G. (1996-03-01). "Visual and Near-Infrared Imaging of Ultraluminous Infrared Galaxies: The IRAS 2 Jy Sample". The Astronomical Journal. 111: 1025. Bibcode:1996AJ....111.1025M. doi:10.1086/117849. ISSN 0004-6256.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-06-08.
  4. ^ Emonts, Bjorn; Morganti, Raffaella; Villar-Martin, Montserrat; Hodgson, Jeff; Brogt, Erik; Tadhunter, Clive; Mahony, Elizabeth; Oosterloo, Tom (December 2016). "From galaxy-scale fueling to nuclear-scale feedback: the merger-state of radio galaxies 3C293, 3C305 & 4C12.50". Astronomy & Astrophysics. 596: A19. arXiv:1609.06539. Bibcode:2016A&A...596A..19E. doi:10.1051/0004-6361/201628592. ISSN 0004-6361.
  5. ^ a b Shaw, M. A.; Tzioumis, A. K.; Pedlar, A. (1992-05-01). "The near-IR and milliarcsec radio structure of PKS 1345+125". Monthly Notices of the Royal Astronomical Society. 256: 6P–10. Bibcode:1992MNRAS.256P...6S. doi:10.1093/mnras/256.1.6P. ISSN 0035-8711.
  6. ^ Batcheldor, Dan; Tadhunter, Clive; Holt, Joanna; Morganti, Raffaella; O’Dea, Christopher P.; Axon, David J.; Koekemoer, Anton (2007-05-20). "Dominant Nuclear Outflow Driving Mechanisms in Powerful Radio Galaxies". The Astrophysical Journal. 661 (1): 70–77. arXiv:astro-ph/0702498. Bibcode:2007ApJ...661...70B. doi:10.1086/515391. ISSN 0004-637X.
  7. ^ Evans, A. S.; Kim, D. C.; Mazzarella, J. M.; Scoville, N. Z.; Sanders, D. B. (1999). "Molecular Gas in the Powerful Radio Nucleus of the Ultraluminous Infrared Galaxy PKS 1345+12". The Astrophysical Journal. 521 (2): L107–L110. arXiv:astro-ph/9907397. Bibcode:1999ApJ...521L.107E. doi:10.1086/312198. Retrieved 2024-06-08.
  8. ^ Liu, F. K.; Zhang, Y. H. (2002-01-01). "A new list of extra-galactic radio jets". Astronomy and Astrophysics. 381 (3): 757–760. arXiv:astro-ph/0212477. Bibcode:2002A&A...381..757L. doi:10.1051/0004-6361:20011572. ISSN 0004-6361.
  9. ^ Mirabel, I. F.; Sanders, D. B.; Kazes, I. (1989-05-01). "Molecular Gas in the Powerful Radio Galaxies Perseus A and 4C 12.50". The Astrophysical Journal. 340: L9. Bibcode:1989ApJ...340L...9M. doi:10.1086/185426. ISSN 0004-637X.
  10. ^ O’Dea, Christopher P.; De Vries, Willem H.; Worrall, D. M.; Baum, Stefi A.; Koekemoer, Anton (2000-02-01). "ASCA Observations of the Gigahertz-peaked Spectrum Radio Galaxies 1345+125 and 2352+495". The Astronomical Journal. 119 (2): 478–485. Bibcode:2000AJ....119..478O. doi:10.1086/301209. ISSN 0004-6256.
  11. ^ O'Dea, Christopher P. (1998-05-01). "The Compact Steep-Spectrum and Gigahertz Peaked-Spectrum Radio Sources". Publications of the Astronomical Society of the Pacific. 110 (747): 493–532. Bibcode:1998PASP..110..493O. doi:10.1086/316162. ISSN 0004-6280.
  12. ^ de Grijp, M. H. K.; Lub, J.; Miley, G. K. (1987-07-01). "Warm IRAS sources. I. A catalogue of AGN candidates from the point source catalog". Astronomy and Astrophysics Supplement Series. 70: 95–114. Bibcode:1987A&AS...70...95D. ISSN 0365-0138.
  13. ^ Joseph, R. D.; Wright, G. S. (1985-05-01). "Recent star formation in interacting galaxies - II. Super starbursts in merging galaxies". Monthly Notices of the Royal Astronomical Society. 214 (2): 87–95. Bibcode:1985MNRAS.214...87J. doi:10.1093/mnras/214.2.87. ISSN 0035-8711.
  14. ^ Sanders, D. B.; Soifer, B. T.; Elias, J. H.; Madore, B. F.; Matthews, K.; Neugebauer, G.; Scoville, N. Z. (1988-02-01). "Ultraluminous Infrared Galaxies and the Origin of Quasars". The Astrophysical Journal. 325: 74. Bibcode:1988ApJ...325...74S. doi:10.1086/165983. ISSN 0004-637X.
  15. ^ "NICMOS Imaging of Infrared-Luminous Galaxies". ned.ipac.caltech.edu. Retrieved 2024-06-08.
  16. ^ Veilleux, S.; Kim, D. -C.; Sanders, D. B.; Mazzarella, J. M.; Soifer, B. T. (1995-05-01). "Optical Spectroscopy of Luminous Infrared Galaxies. II. Analysis of the Nuclear and Long-Slit Data". The Astrophysical Journal Supplement Series. 98: 171. Bibcode:1995ApJS...98..171V. doi:10.1086/192158. ISSN 0067-0049.
  17. ^ Sanders, D. B.; Soifer, B. T.; Elias, J. H.; Neugebauer, G.; Matthews, K. (1988-05-01). "Warm Ultraluminous Galaxies in the IRAS Survey: The Transition from Galaxy to Quasar?". The Astrophysical Journal. 328: L35. Bibcode:1988ApJ...328L..35S. doi:10.1086/185155. ISSN 0004-637X.
  18. ^ Holt, J.; Tadhunter, C. N.; Morganti, R. (2003). "2003MNRAS.342..227H Page 228". Monthly Notices of the Royal Astronomical Society. 342 (1): 227. arXiv:astro-ph/0302311. Bibcode:2003MNRAS.342..227H. doi:10.1046/j.1365-8711.2003.06532.x. Retrieved 2024-06-08.
  19. ^ Heckman, T. M.; Smith, Eric P.; Baum, Stefi A.; van Breugel, W. J. M.; Miley, G. K.; Illingworth, G. D.; Bothun, G. D.; Balick, B. (1986-12-01). "Galaxy Collisions and Mergers: The Genesis of Very Powerful Radio Sources?". The Astrophysical Journal. 311: 526. Bibcode:1986ApJ...311..526H. doi:10.1086/164793. ISSN 0004-637X.
  20. ^ Veilleux, Sylvain; Sanders, D. B.; Kim, D. -C. (1997-07-01). "A Near-Infrared Search for Hidden Broad-Line Regions in Ultraluminous Infrared Galaxies". The Astrophysical Journal. 484 (1): 92–107. Bibcode:1997ApJ...484...92V. doi:10.1086/304337. ISSN 0004-637X.
  21. ^ Holt, J.; Tadhunter, C. N.; Morganti, R. (2003). "2003MNRAS.342..227H Page 229". Monthly Notices of the Royal Astronomical Society. 342 (1): 227. arXiv:astro-ph/0302311. Bibcode:2003MNRAS.342..227H. doi:10.1046/j.1365-8711.2003.06532.x. Retrieved 2024-06-08.
  22. ^ Mirabel, I. F. (1989-05-01). "Atomic Hydrogen in the Powerful Radio-Infrared Galaxies 4C 12.50 and 3C 433". The Astrophysical Journal. 340: L13. Bibcode:1989ApJ...340L..13M. doi:10.1086/185427. ISSN 0004-637X.
  23. ^ a b Morganti, R.; Oosterloo, T. A.; Tadhunter, C. N.; Vermeulen, R.; Pihlström, Y. M.; Moorsel, G. van; Wills, K. A. (2004-09-01). "The unfriendly ISM in the radio galaxy 4C 12.50 (PKS 1345+12)". Astronomy & Astrophysics. 424 (1): 119–124. arXiv:astro-ph/0406012. Bibcode:2004A&A...424..119M. doi:10.1051/0004-6361:20041064. ISSN 0004-6361.
  24. ^ Rodríguez Zaurín, J.; Holt, J.; Tadhunter, C. N.; González Delgado, R. M. (2007-03-01). "A census of young stellar populations in the warm ULIRG PKS 1345+12". Monthly Notices of the Royal Astronomical Society. 375 (4): 1133–1145. arXiv:astro-ph/0612578. Bibcode:2007MNRAS.375.1133R. doi:10.1111/j.1365-2966.2006.11379.x. ISSN 0035-8711.
  25. ^ Lister, M. L.; Kellermann, K. I.; Vermeulen, R. C.; Cohen, M. H.; Zensus, J. A.; Ros, E. (2003). "4C +12.50: A Superluminal Precessing Jet in the Recent Merger System IRAS 13451+1232". The Astrophysical Journal. 584 (1): 135–146. arXiv:astro-ph/0210372. Bibcode:2003ApJ...584..135L. doi:10.1086/345666.
  26. ^ a b Holt, J.; Tadhunter, C. N.; Morganti, R. (2003-06-11). "Highly extinguished emission line outflows in the young radio source PKS 1345+12". Monthly Notices of the Royal Astronomical Society. 342 (1): 227–238. arXiv:astro-ph/0302311. Bibcode:2003MNRAS.342..227H. doi:10.1046/j.1365-8711.2003.06532.x. ISSN 0035-8711.
  27. ^ Holt, J.; Tadhunter, C. N.; Morganti, R. (2003). "Extreme emission line outflows in the GPS source 4C 12.50 (PKS 1345+12)". Publications of the Astronomical Society of Australia. 20 (1): 25–27. arXiv:astro-ph/0210092. Bibcode:2003PASA...20...25H. doi:10.1071/AS02038. ISSN 1323-3580.
  28. ^ Holt, J.; Tadhunter, C. N.; Morganti, R.; Emonts, B. H. C. (October 2010). "The impact of the warm outflow in the young (GPS) radio source & ULIRG PKS 1345+12 (4C 12.50)". Monthly Notices of the Royal Astronomical Society: no. arXiv:1008.2846. doi:10.1111/j.1365-2966.2010.17535.x.
Quelle: http://en.wikipedia.org/wiki/PKS_1345%2B125