PG 0844+349

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PG 0844+349
PG 0844+349 and its companion galaxy captured by SDSS
Observation data (J2000 epoch)
ConstellationLynx
Right ascension08h 47m 42.47s
Declination+34d 45m 04.40s
Redshift0.064000
Heliocentric radial velocity19,187 km/s
Distance849 Mly (260.3 Mpc)
Apparent magnitude (V)0.10
Apparent magnitude (B)0.13
Surface brightness13.5
Characteristics
TypeSp (d), Sy1,
Notable featuresSeyfert galaxy containing a quasar
Other designations
TON 951, RBS 724, PGC 24702, RX J0847.6+3445, LAMOST J084742.44+344504.4, CSO 204, 2E 2048, 1ES 0844+349, 2PBC J0848.2+3443

PG 0844+349, also known as TON 951 (abbreviation of Tonantzintla 951), is a galaxy in the southern constellation Lynx, near the border of Cancer. Its redshift is 0.064000, putting the galaxy at 849 million light-years away from Earth.[1]

Observation history[edit]

PG 0844+349 was first discovered in 1957 by the Tonantzintla Observatory who was searching for blue stellar objects (mainly white dwarfs) as quasar candidates.[2] Because quasars were not identified until 1963,[3] the nature of this object was unknown. Studying photographic plates that were taken with the 0.7 m Schmidt telescope, it was discovered PG 0844+349 has a Seyfert 1 spectrum, classifying it as a quasar. Mexican astronomers Braulio Iriate and Enrique Chavira subsequently listed it as the 951st object in the Tonantzintla Catalogue.[4] The same case was applied with TON 618.

In 2009, PG 0844+349 was observed again, by the Swift observatory, and it was noted to have a weak X-ray state. Several weeks later, a follow-up observation by XMM-Newton found it showing a spectral hardening and substantial curvature. This shows that PG 0844+349 is in the phase of reflection-dominated state and its light bending scenario can be accounted for short-term ( ∼1000 s) spectral variability in its source.[5]

Characteristics[edit]

PG 0844+349 has an active galactic nucleus. It is classified a Seyfert type 1.0 galaxy,[6] containing two sets of emission lines superimposed onto each other. One set of lines is a low-density (electron density ne  103-106 cm−3) ionized gas that has widths which corresponds to velocities of several hundred kilometers per second. The other is a set of broad lines, with widths as high as 104 km s−1; but the absence of broad forbidden-line emission indicates that the broad-line gas is of high density (ne  109 cm−3 or higher).[7] It can be said PG 0844+349 is a narrow-line Seyfert 1 galaxy considered having all characteristics of type 1 Seyfert galaxies,[8] but it does not have any hardness ratio variations as a single observation finds no strong correlation between the hardness ratio and the continuum luminosity.[9]

PG 0844+349 is also a quasar but with low luminosity.[2] The quasar host is a disturbed face-on barred spiral galaxy,[10][11] which is found interacting with its companion galaxy, 2MASX J08474179+3444405.[12] Both galaxies show signs of gravitational distortion, in which tidal tails and a hot blue stellar component can be seen.[2] Through the interaction with 2MASX J08474179+3444405, this causes the activity in the central region of PG 0844+349 to awaken causing it to create more star formation with its black hole mass suppressed by its increasing starburst luminosity.[13] This gives it its quasar appearance.

Observation[edit]

In a 2002 observation of PG 0844+349, it was found to be in a historically high state compared to the prior observation by X-rays. This shows a featureless spectrum containing a strong soft excess that is over the extrapolation of a hard power law. From the acceptable descriptions of the spectral continuum, the comptonization model is represented by its Gamma_{soft} ~ 2.75, Gamma_{hard} ~ 2.25 and a break energy of E_{break} of ~ 1.35 keV, meaning the temperature is low and have a higher optical depth than in broad-line Seyfert galaxies. Further observation shows the flux in PG 0844+349 varying achromatically on its time scale, in relatively few seconds by ~ 25%. This puts constraints on the current models of Comptonizing accretion disk coronae.[14]

According to observation from the ASCA satellite, researchers has found PG 0844+349 has a high state with a photon index of 1.98 and an Fe Kα line with EW ~ 300 eV. Even its X-ray flux ranging in the 2-10 keV band is considered highly variable. They found that the fastest variation detected reaches up to 2 × 104 s but less than 60%. Given the state of PG 0844+349, the measured excess variance fits well in comparison with the L2-10 keV relation for Seyfert 1 galaxies; the flux variability in the 0.5-2.0 keV band has a slightly higher amplitude than in the 2-10 keV band. Researchers noted the optical microvariability of PG 0844+349 is driven by reprocessing of variable X-ray fluxes, provided one-half of its absorbed X-rays are reradiated in the optical-to-ultraviolet band.[15]

Black hole[edit]

The supermassive black hole in PG 0844+349 has an estimated solar mass of 2.138×107.[16] This makes the galaxy contain one of the largest black holes, but a lower black hole mass putting it between Messier 58 and Centaurus A. Only TON 618 has a higher black hole solar mass of 4.07×1010 compared to PG 0844+349.[17]

References[edit]

  1. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-05-28.
  2. ^ a b c "0844+349". quasar.square7.ch. Retrieved 2024-05-28.
  3. ^ "1963: Maarten Schmidt Discovers Quasars | Everyday Cosmology". 2019-02-01. Archived from the original on 2019-02-01. Retrieved 2024-05-28.
  4. ^ Braulio, Iriarte; Chavira, Enrique. ""Estrellas Azules en el Casquete Galactico Norte (Blue stars in the North Galactic Cap)"" (PDF).
  5. ^ Gallo, L. C.; Grupe, D.; Schartel, N.; Komossa, S.; Miniutti, G.; Fabian, A. C.; Santos-Lleo, M. "The quasar PG 0844+349 in an X-ray weak state". academic.oup.com. Retrieved 2024-05-28.
  6. ^ 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.
  7. ^ "Seyfert Galaxies". ned.ipac.caltech.edu. Retrieved 2024-05-28.
  8. ^ Tarchi, A.; Castangia, P.; Columbano, A.; Panessa, F.; Braatz, J. A. (2011-08-01). "Narrow-line Seyfert 1 galaxies: an amasing class of AGN". Astronomy & Astrophysics. 532: A125. arXiv:1107.5155. Bibcode:2011A&A...532A.125T. doi:10.1051/0004-6361/201117213. ISSN 0004-6361.
  9. ^ Brinkmann, W.; Wang, T.; Grupe, D.; Raeth, C. (2006-05-01). "PG 0844+349 revisited – is there any outflow?". Astronomy & Astrophysics. 450 (3): 925–931. Bibcode:2006A&A...450..925B. doi:10.1051/0004-6361:20053751. ISSN 0004-6361.
  10. ^ Brinkmann, W.; Grupe, D.; Branduardi-Raymont, G.; Ferrero, E. "XMM-Newton observation of PG 0844+349" (PDF).
  11. ^ Le, Huynh Anh Nguyen; Pak, Soojong; Im, Myungshin; Kim, Minjin; Sim, Chae Kyung; Ho, Luis C. (2014-09-01). "Medium resolution near-infrared spectra of the host galaxies of nearby quasars". Advances in Space Research. 54 (6): 1129–1134. arXiv:1405.4984. Bibcode:2014AdSpR..54.1129L. doi:10.1016/j.asr.2014.05.023. ISSN 0273-1177.
  12. ^ "NED Search Results for WISEA J084741.74+344440.6". ned.ipac.caltech.edu. Retrieved 2024-05-28.
  13. ^ Watabe, Y.; Kawakatu, N.; Imanishi, M.; Takeuchi, T. T. "Supermassive black hole mass regulated by host galaxy morphology". academic.oup.com. Retrieved 2024-05-28.
  14. ^ Brinkmann, W.; Grupe, D.; Branduardi-Raymont, G.; Ferrero, E. (2003-01-01). "XMM-Newton observation of PG 0844+349". Astronomy & Astrophysics. 398 (1): 81–87. arXiv:astro-ph/0211479. Bibcode:2003A&A...398...81B. doi:10.1051/0004-6361:20021608. ISSN 0004-6361.
  15. ^ Wang, T. G.; Brinkmann, W.; Matsuoka, M.; Wang, J. X.; Yuan, W. (2000-04-10). "X-Ray and Ultraviolet Spectral Properties of theX-Ray Transient QuasarPG 0844+349". The Astrophysical Journal. 533 (1): 113. Bibcode:2000ApJ...533..113W. doi:10.1086/308630. ISSN 0004-637X.
  16. ^ Nelson, Charles H. (2000-12-01). "Black Hole Mass, Velocity Dispersion and the Radio Source in AGN". The Astrophysical Journal. 544 (2): L91–L94. arXiv:astro-ph/0009188. doi:10.1086/317314.
  17. ^ Ge, Xue; Zhao, Bi-Xuan; Bian, Wei-Hao; Frederick, Green Richard (2019-03-20). "The Blueshift of the C iv Broad Emission Line in QSOs". The Astronomical Journal. 157 (4): 148. arXiv:1903.08830. Bibcode:2019AJ....157..148G. doi:10.3847/1538-3881/ab0956. ISSN 0004-6256.
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