Wikipedia

PKS 0529-549

PKS 0529-549 known as MRC 0529-549 and PKS B0529-549, is a radio galaxy located in the constellation Pictor. At the redshift of 2.57, the object is located nearly 10.8 billion light-years away from Earth.[1]

PKS 0529-549
Observation data (J2000.0 epoch)
ConstellationPictor
Right ascension05h 30m 25.21s
Declination-54d 54m 22.1s
Redshift2.574360
Heliocentric radial velocity771,774 km/s
Distance10.782 Gly (light travel time distance)
Apparent magnitude (V)0.171
Apparent magnitude (B)0.227
Surface brightness20.0
Notable featuresRadio galaxy, starburst galaxy
Other designations
PGC 2824392, PKS B0529-549, MRC 0529-549, PMMM 052927.1-545647, SUMSS J053025-545422

Characteristics

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PKS 0529-549 is one of the high redshift radio galaxies (HzRGs) found.[2][3][4] Detected from high-resolution 12-mm and 3-cm images, obtained by the Australia Telescope Compact Array, the galaxy is found to have a Type-II active galactic nucleus (AGN) showing two radio lobes. With a rest-frame of -9600 rad m-2, the eastern radio lobe holds a record for the highest Faraday rotation measure to date, signifying a strong magnetic field or either a dense circumgalactic medium.[5]

The host galaxy for PKS 0529-549 is a starburst galaxy[6] in the final stages of merging with another galaxy.[7] The result of this galaxy merger would be progenitor of an elliptical galaxy, in which causes increasing luminosity due to high star formation in its regions.[8] Signs of star formation included a plethora of absorption line features detected through using the deep X-shooter spectrum, stellar photospheric and wind features indicating presence of OB-type stars as well as both emission lines and low-ionization absorption features.[7]

From further observations, PKS 0529-549 has an energetic source of radiation located throughout most of the electromagnetic spectrum. Such HzRGs like PKS 0529-549 are extremely massive, including old stars (up to ~ 1012 M○), hot gas (up to ~ 1012 M○) and molecular gas (up to ~ 1011 M○).[9] Furthermore, galaxies with M⋆ ≳1011 M⊙ at z ≃ 2–3 tend to have star formation rates of order of ~100 M⊙ yr−1. This suggests PKS 0529-549 lies above the mean SFR–M⋆ relation, in the so-called star-forming main sequence.[10]

Like most HzRGs, PKS 0529-549 is known to host large reservoirs of interstellar dust and gas.[11] Apart from that, the galaxy is found to exhibit both hot dust emission at 8.0 μm, with a significant internal visual extinction (~1.6 mag), inferred from Spitzer Space Telescope near/mid-IR imaging.[5]

Observations

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According to researchers who observed PKS 0529-549 from Atacama Large Millimeter Array in Chile, it contains chlorine [C I] and doubly ionized oxygen [O III] which display regular velocity gradients. However, their systemic velocities and kinematic PAs differ by ~300 km s−1 and ~30°, respectively. The [C I] is consistent with a rotating disc, meaning it is aligned together with both the stellar and dust components, while the [O III] has a possible outflow trace, that is aligned with two active galactic nuclei-driven radio lobes in the host galaxy of PKS 0529–549.

Moreover, the [C I] cube is reproduced through a 3D disc model with Vrot ≃ 310 km s−1 and σV ≲ 30 km s−1⁠, giving Vrot/σV ≳10, comparable to local spiral galaxies.[12][13] This indicates that the [C I] disc of PKS 0529-549 is not particularly turbulent[14] and indeed remarkable considering that PKS 0529-549 has a star formation at the rate of at ~1000 M⊙ yr−1. Not to mention, it hosts a powerful radio-loud active galactic nucleus, with large amount of energy injected into its interstellar medium.[15]

PKS 0529-549 is known to lie on the local baryonic Tully–Fisher relation. This is interesting since it has both estimates of both M⋆ and Mmol, other than Vrot and σV according to researchers who studied the galaxy. The stellar mass of PKS 0529-549 according to them, are estimated to be M⋆/L[3.6] = 0.5 M○/L○ which is similar for all galaxies, as expected from stellar population synthesis models with a Kroupa IMF.[16]

Researchers further measured the rotation velocities along the flat part of the rotation curve (Vflat) in PKS 0529–549. This is probed by deep H I observations by Spitzer Photometry and Accurate Rotation Curves.[17] In the case, Vrot is an intensity-weighted estimate over the semimajor axis, since the [C I] emission is resolved with ~2 beams. Thus, one might wonder whether they are probing Vflat. Local galaxies that have similar masses as PKS 0529-549 normally have rotation curves, peaking at very small radii (R ≲ 1 kpc). These tend to decline by around ~20–30 percent before reaching Vflat.[18] This suggests some massive galaxies like PKS 0529-549 are in place and kinematically relaxed at z ≃ 2.6, when the universe was only ~2.5 billion years old.[14]

References

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  1. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-06-05.
  2. ^ "Distant Radio Galaxies and their Environments - G.K. Miley & C. De Breuck". ned.ipac.caltech.edu. Retrieved 2024-06-05.
  3. ^ De Breuck, Carlos; Klamer, Ilana; Johnston, Helen; Hunstead, Richard W.; Bryant, Julia; Rocca-Volmerange, Brigitte; Sadler, Elaine M. (2006-02-01). "A search for distant radio galaxies from SUMSS and NVSS - II. Optical spectroscopy1*". Monthly Notices of the Royal Astronomical Society. 366 (1): 58–72. arXiv:astro-ph/0511169. Bibcode:2006MNRAS.366...58D. doi:10.1111/j.1365-2966.2005.09799.x. ISSN 0035-8711.
  4. ^ Broderick, Jess; De Breuck, Carlos; Hunstead, Richard (2006-04-01). "High resolution polarimetric imaging of PKS 0529-549: A pilot study at 12 mm". ATNF Proposal: C1555. Bibcode:2006atnf.prop..221B.
  5. ^ a b Broderick, J. W.; De Breuck, C.; Hunstead, R. W.; Seymour, N. (2007-03-01). "An extreme rotation measure in the high-redshift radio galaxy PKS B0529-549". Monthly Notices of the Royal Astronomical Society. 375 (3): 1059–1069. arXiv:astro-ph/0612143. Bibcode:2007MNRAS.375.1059B. doi:10.1111/j.1365-2966.2006.11375.x. ISSN 0035-8711.
  6. ^ Singh, V.; Beelen, A.; Wadadekar, Y.; Sirothia, S.; Ishwara-Chandra, C. H.; Basu, A.; Omont, A.; McAlpine, K.; Ivison, R. J.; Oliver, S.; Farrah, D.; Lacy, M. (2014-09-01). "Multiwavelength characterization of faint ultra steep spectrum radio sources: A search for high-redshift radio galaxies". Astronomy & Astrophysics. 569: A52. arXiv:1405.1737. Bibcode:2014A&A...569A..52S. doi:10.1051/0004-6361/201423644. ISSN 0004-6361.
  7. ^ a b Man, Allison W. S.; Lehnert, Matthew D.; Vernet, Joël D. R.; Breuck, Carlos De; Falkendal, Theresa (2019-04-01). "Quenching by gas compression and consumption - A case study of a massive radio galaxy at z = 2.57". Astronomy & Astrophysics. 624: A81. arXiv:1902.08622. Bibcode:2019A&A...624A..81M. doi:10.1051/0004-6361/201834542. ISSN 0004-6361.
  8. ^ Eales, Stephen A.; Rawlings, Steve (1996-03-01). "A Panoramic View of Radio Galaxy Evolution from a Redshift of 0 to a Redshift of 4.3". The Astrophysical Journal. 460: 68. Bibcode:1996ApJ...460...68E. doi:10.1086/176953. ISSN 0004-637X.
  9. ^ Miley, G.; Carilli, C.; Taylor, G. B.; de Breuck, C.; Cohen, A. (2009-02-01), High Redshift Radio Galaxies: Laboratories for Massive Galaxy and Cluster Formation in the early Universe, arXiv:0902.3677, retrieved 2024-06-05
  10. ^ Bisigello, L.; Caputi, K. I.; Grogin, N.; Koekemoer, A. (2018-01-01). "Analysis of the SFR-M∗ plane at z < 3: single fitting versus multi-Gaussian decomposition". Astronomy and Astrophysics. 609: A82. arXiv:1706.06154. Bibcode:2018A&A...609A..82B. doi:10.1051/0004-6361/201731399. ISSN 0004-6361.
  11. ^ J. Willott, Chris; Rawlings, Steve; J. Jarvis, Matt; M. Blundell, Katherine. "Near-infrared imaging and the K—z relation for radio galaxies in the 7C Redshift Survey". academic.oup.com. Retrieved 2024-06-05.
  12. ^ Leroy, Adam K.; Walter, Fabian; Brinks, Elias; Bigiel, Frank; de Blok, W. J. G.; Madore, Barry; Thornley, M. D. (2008-12-01). "The Star Formation Efficiency in Nearby Galaxies: Measuring Where Gas Forms Stars Effectively". The Astronomical Journal. 136 (6): 2782–2845. arXiv:0810.2556. Bibcode:2008AJ....136.2782L. doi:10.1088/0004-6256/136/6/2782. ISSN 0004-6256.
  13. ^ Mogotsi, K. M.; de Blok, W. J. G.; Caldú-Primo, A.; Walter, F.; Ianjamasimanana, R.; Leroy, A. K. (2016-01-01). "H I and CO Velocity Dispersions in Nearby Galaxies". The Astronomical Journal. 151 (1): 15. arXiv:1511.06006. Bibcode:2016AJ....151...15M. doi:10.3847/0004-6256/151/1/15. ISSN 0004-6256.
  14. ^ a b Lelli, Federico; De Breuck, Carlos; Falkendal, Theresa; Fraternali, Filippo. "Neutral versus ionized gas kinematics at z ≃ 2.6: the AGN-host starburst galaxy PKS 0529-549". academic.oup.com. Retrieved 2024-06-05.
  15. ^ Lehnert, M. D.; Nesvadba, N. P. H.; Le Tiran, L.; Di Matteo, P.; van Driel, W.; Douglas, L. S.; Chemin, L.; Bournaud, F. (2009-07-01). "Physical Conditions in the Interstellar Medium of Intensely Star-Forming Galaxies at Redshift~2". The Astrophysical Journal. 699 (2): 1660–1678. arXiv:0902.2784. Bibcode:2009ApJ...699.1660L. doi:10.1088/0004-637X/699/2/1660. ISSN 0004-637X.
  16. ^ Kroupa, Pavel (2001-04-01). "On the variation of the initial mass function". Monthly Notices of the Royal Astronomical Society. 322 (2): 231–246. arXiv:astro-ph/0009005. Bibcode:2001MNRAS.322..231K. doi:10.1046/j.1365-8711.2001.04022.x. ISSN 0035-8711.
  17. ^ Lelli, Federico; McGaugh, Stacy S.; Schombert, James M. (2016-12-01). "SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and Accurate Rotation Curves". The Astronomical Journal. 152 (6): 157. arXiv:1606.09251. Bibcode:2016AJ....152..157L. doi:10.3847/0004-6256/152/6/157. ISSN 0004-6256.
  18. ^ Noordermeer, E.; van der Hulst, J. M.; Sancisi, R.; Swaters, R. S.; van Albada, T. S. (2007-04-01). "The mass distribution in early-type disc galaxies: declining rotation curves and correlations with optical properties". Monthly Notices of the Royal Astronomical Society. 376 (4): 1513–1546. arXiv:astro-ph/0701731. Bibcode:2007MNRAS.376.1513N. doi:10.1111/j.1365-2966.2007.11533.x. ISSN 0035-8711.
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