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PKS 1345+125

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PKS 1345+125
PKS 1345+125 captured bySDSS
Observation data (J2000.0epoch)
ConstellationBoötes
Right ascension13h 47m 33.36s
Declination+12d 17m 24.24s
Redshift0.121740
Heliocentric radial velocity36,497km/s
Distance1.699Gly(521Mpc)
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,IRAS13451+1232,PGC48898, OP +175,NVSSJ134733+121724,FIRSTJ134733.3+121724, GB6 J1347+1217, TXS 1345+125, CoNFIG 177,MRC1345+125,PKSB1345+125

PKS 1345+125known asPKS 1345+12and4C +12.50,is anultraluminous infrared galaxy(ULIG)[1][2]with anactive galactic nucleus,located in the constellationBoötes.With aredshiftof 0.121740, the galaxy is located 1.7 billionlight-yearsfromEarth.[3]

Characteristics

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Amergerof two gas-rich galaxies consisting of oneellipticaland onespiral,[4][5]PKS 1345+125 is the powerfulradio galaxy[6]ever detected in CO (1 → 0) to date with a radioluminosityofP408 MHz= 2.4 × 1026W Hz−1.[7]It presents a compactastrophysical jet[8]that is 0.1 "~200 pc wide, a highmolecular gasmass measuring 4.4 × 1010M[9]and contains agigahertzpeaked-spectrumradio source(GPS)[10]within the extent of itsnarrow-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 m0.2, that is similar to the colors ofSeyfert galaxies.[12]Such infrared galaxies like PKS 1345+125, are in atransition statebetween the "cold" (f25 m/f60 m< 0.2) ULIGphenomenon,where activestar formationare occurring,[13]with theiraccretion disksforming 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 opticalemission lines;this indicatesSeyfert 2 activity.[16][17]The twonucleiin the galaxy have a projected separation of ≈ 2″ ~ 4 kpc and are surrounded by an extended asymmetricalgalactic halothat is detected in bothinfraredandoptical images.[18]These signs shows bothblack holesare on a verge of merging.[19]Furthermore, a powerful obscuredquasarnucleus atwavelengths,is detected with a broad (△vFWHM~ 2600 km s−1) Pa emission, through recent near-infraredspectroscopic observations.[20][21]

In addition to narrow optical emission lines, the columndensitiesof 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 toArp 220,the infrared andinterstellar gasproperties are higher in PKS 1345+125.[22]

Observation of PKS 1345+125

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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 neutralhydrogeninside nuclear regions of this object, they showed mostgasdetected close to the systemicvelocity,are found to be associated with an off-nuclear cloud ( ~ 50 to 100 pc from its radio core. Not to mention, the gas has acolumn densityof 1022Tspin/100 k cm−2with a H1 mass of 105to 106M○.[23]

From the results, researchers hinted theinterstellar cloudin PKS 1345+125 has presence of rich and clumpyinterstellar mediumlocated 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 northernradio lobeaccording 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 ofkinematicalevidence for interaction of the radioplasmawith the cloud.[23]

Through imaging withHubble Space Telescopeand long-slit spectra by theWilliam Herschel TelescopeatLa PlamainSpain,researchers detected youngstellar populationsin PKS 1345+125 with bright blue knots indicating superstar clusters.These star clusters are found to have ages of tSSC< 6Myr with reddenings 0.2 < E(B - V) < 0.5 andsolar massesof 106< MYSPSSC< 107Msolar.The young stellar populations meanwhile, are indiffuse lightthat 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. Thelong-slit spectrashows they are moving at 450 km−1in respect to localambient 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

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The radio source in PKS 1345+125 is found to be a compact symmetric source[25]according to researchers who observed it in optical andinfra-red images.An extendedline emissionaround ~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 HIabsorption,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, theelectrondensities 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

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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 smallfraction(0.13% of Lbol) of theaccretionpower available are driving the warm outflows. This is significantly less compared to accretion power required by majority of quasarfeedbackmodels (~5-10\% of Lbol). Although the model predicted the gas is removed through active galactic nucleus outflows from thehost 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 foractive galactic nuclei.[28]

References

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  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.ISSN0004-6256.{{cite journal}}:CS1 maint: multiple names: authors list (link)
  3. ^"Your NED Search Results".ned.ipac.caltech.edu.Retrieved2024-06-08.
  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.ISSN0004-6361.
  5. ^abShaw, 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.ISSN0035-8711.
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  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.ISSN0004-6256.
  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.ISSN0004-6280.
  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.ISSN0365-0138.
  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.ISSN0035-8711.
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  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.ISSN0004-637X.
  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.Retrieved2024-06-08.
  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.ISSN0004-637X.
  23. ^abMorganti, 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.ISSN0004-6361.
  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.ISSN0035-8711.
  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. ^abHolt, 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.ISSN0035-8711.
  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.ISSN1323-3580.
  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.