Wikipedia

I Zwicky 1

I Zwicky 1 (shortened to I Zw 1), also known as UGC 545, is a galaxy located in the constellation Pisces. It is located 847 million light-years from Earth[1] and is said to be the nearest quasar (QSO) due to its high optical nuclear luminosity of MV = -23.8 mag.[2]

I Zwicky 1
Hubble Space Telescope image of I Zwicky 1
Observation data (J2000 epoch)
ConstellationPisces
Right ascension00h 53m 34.94s
Declination+12d 41m 36.20s
Redshift0.061169
Heliocentric radial velocity18,338 km/s
Distance847 Mly (259.7 Mpc)
Apparent magnitude (V)0.43
Apparent magnitude (B)0.54
Surface brightness14.4
Characteristics
TypeSa;Sy1, Sbrst
Size0.5' x 0.5'
Notable featuresSeyfert galaxy containing a quasar
Other designations
UGC 545, PG 0050+124, PGC 3151, IRAS 00509+1225, RBS 0129, 2E 209, PHL 3072, Mrk 1502, Mrk 9009, NVSS J005334+124133

Discovery edit

I Zwicky 1 was discovered by Fritz Zwicky in 1964. According to Zwicky, the object is classified as a compact galaxy, whom he commented it as "variable blue spherical, very compact, with a patchy halo. It is listed as the first object in the Zwicky catalogue.[3] At the redshift of 0.0611,[4] I Zwicky 1 shows spectral properties of high-redshift quasars that are blueshifted by 1350 km-1 according to the study conducted by Buson & Ulrich in 1990.[5]

The photometric history of I Zwicky 1, dates back to 1909, where it has been investigated on Harvard photographic plates. The available data indicates the galaxy is variable and probably undergoes outbursts of about 0.7 mag above a brightness level that is itself variable by about 0.7 mag.[6]

Characteristics edit

 
Sloan Digital Sky Survey of I Zwicky 1

The nucleus of I Zwicky 1 is found to be active. It is classified as a prototypical narrow-line Seyfert 1 galaxy[7][8][9] and contains high amounts of X-ray luminosity.[10][11] The galaxy contains a peculiar spectrum, which in addition to the usual broad and narrow line regions, there are two emission regions emitting broad and blue shifted [O III] lines making it a peculiarly interesting object.[12] The QSO sits inside its host galaxy which is revealed to be a face-on spiral galaxy. It shows two asymmetric spiral arms and knots of star formation.[3] This makes I Zwicky 1 an ideal candidate for studying properties of QSO hosts.[2] It is also possible that certain tidal interactions triggers activity in I Zwicky 1, both starburst and QSO.[13]

I Zwicky 1 is classified a Markarian galaxy (designated both Mrk 1502 and Mrk 9009). Compared to other galaxies, the nucleus emits excessive amounts of ultraviolet rays.[14] This is caused by undergoing a strong starburst located in the central ring-like area of the galaxy.[3]

Further study on I Zwicky 1 edit

I Zwicky 1 shows presence of V-, R-, and H-bands[15][16] and strong carbon monoxide (CO) in the J = 1-0 and J = 2-1 lines. From further investigation, researchers found that the J = 1-0 line appears to be luminous than the J = 2-1 line. They found out for the CO to be extended on the scale of the larger J = 1-0 beam size (26 kpc), it must be optically thick and thermalized, given its location in galactic molecular clouds.[17]

Moreover, another research studying interstellar medium and star formation, found out there is a need of a two-component model for I Zwicky 1 in which about 2/3 of the far- infrared luminosity originates in the disk and 1/3 originates in the nucleus. The star-forming rate, efficiency of the disk and the nucleus of I Zwicky 1 was estimated by researchers, whom found that the values are comparable to luminous IRAS galaxies. Overall, the star-formation inside the disc, is closer to maximum values of ~30 L_sun_/M_sun_ found in Galactic star-forming regions like M17 or W51. The nuclear near-infrared colors analysis, suggests there is a mixture of a QSO nucleus and an extinct stellar component contributing about 10%-20% of the flux density at 2.2 microns.[18] This suggests an estimate of the molecular bulge size of the order of 1" to 2" (1.2-2.4 kpc). But the presence of the nucleus, is only optically revealed through the optical spectrum and large X-ray luminosity.[18]

Millimeter Spectroscopy

Further studies showed the mapping of 12CO (10) line emission in I Zwicky 1 between January and February 1995, taken using with the Institut de Radio Astronomie Millimetrique (IRAM) millimeter interferometer on the Plateau de Bure, in France.[19] There, four 15 m antennas were positioned in four different configurations. They provided 24 baselines, ranging from 24 to 288 m in length and were equipped with SIS receivers with single-sideband (SSB) system temperatures of 170 K above the atmosphere. It was found that the observed frequency was 108.633 GHz because I Zwicky 1 is located at the redshift of z = 0.0611.

The CO maps were made through observation from IRAM 30m telescope. The resolution of the synthesized beam was found to be 19 (uniform weighting), but 5 resolution CLEAN maps (natural weighting) were made with spectral resolutions of 10 km s−1 and 40 km s−1 to study the extended disk structure and velocity field. For the studies of the core component, researchers used the 19 resolution CLEANed maps with a spectral resolution of 20 km s−1. To investigate the dynamics of the nucleus, they calculated velocity maps as well as p-v diagrams along the major and minor kinematic axes of I Zwicky 1.[2]

Near-Infrared Spectroscopy and Imaging

I Zwicky 1 was observed in the K-band (2.20 m) in 1995 January with the MPE imaging spectrometer utilizing 3D images[20] at the 3.6 m telescope in Calar Alto, Spain. The observations in the H-band (1.65 m) were carried out in 1995 December at the William Herschel Telescope in La Palma, Canary Islands. From both observations, researchers found that the image scale was 05 pixel−1. The total integration time on source was 4200 s for the K-band and 1530 s for the H-band.[2]

Molecular gas properties edit

The properties of the molecular gas is said to be essential to understanding star formation and the fueling of AGNs, as molecular clouds are the major reservoir for these phenomena. According to researchers, they detected molecular line emission inside the spiral arms of the QSO host galaxy. They were able to decompose the line emission into a core and disk component. Through analyzing the velocity field, they have found a circumnuclear ring of molecular gas whose size is similar to those of starburst rings found in nearby galaxies. At the spatial resolution of 19 (2.2 kpc), they saw no obvious sign of gas streaming directly into the very nucleus.[2]

Comparison of starburst rings edit

In a study where starburst rings are observed in galaxies,[21] the rings in I Zwicky 1 is thought to be formed through gravitational interactions, because of stars and gas. These are detected in the midinfrared continuum, near-infrared colors, and molecular gas line emission, as well as in H line emission. Although, the overall structure of these rings is not entirely smooth, they could possibly be formed by two spiral arms tightly twisted around the nucleus.[2] To see whether the rings are distinct or common, researchers investigated two other galaxies, NGC 7552 and NGC 7469. They found that the properties of these rings are similar to one another in all three galaxies. But there differences in the total bolometric luminosity might be linked to the internal structure of the rings, and therefore to fueling of the individual starburst regions within the ring.[2]

The starburst in the rings of I Zwicky 1 is about 3 times older than those in NGC 7552 and NGC 7469. Uisng this comparison, it would seem that the molecular ring, researchers detected in the 12CO(10) line emission, is hosting a starburst similar to those found in other circumnuclear rings. This indicates that a fraction of the high luminosity observed for QSOs and Seyfert galaxies is mainly due to a circumnuclear starburst in the centers of their host galaxies, and that the AGNs are not solely responsible for the overall energy output in the optical and infrared.[2] The contribution of the star formation activity to the bolometric luminosity can range from only about 10%, as in the case of I Zwicky 1, to about 50%, as observed for NGC 7469.[22]

To sum things up, they found that a young, massive, and decaying starburst is associated with this circumnuclear ring. The properties of this starburst ring in I Zwicky 1, are similar to the ones observed in other sources with nuclear activity. These similarities indicate that these rings may be a common phenomenon and contribute a significant fraction to the central luminosity.[2]

Supermassive black hole edit

The supermassive black hole in I Zwicky 1, is said to have a mass of M. = 9.30 (+1.26 divided by - 1.38) x 10 (power of 6) M○ according to researchers calculating the mean spectra. This suggests the accretion rate to be 203.9 (+61.0 divided by -65.8) L edd c-2, indicating a super-Eddington accretor, where LEdd is the Eddington luminosity and c is the speed of light. By decomposing Hubble Space Telescope images, we find that the stellar mass of the bulge of its host galaxy equals to log(M budge/M○ = 10.92 + 0.07. This leads to a black hole to bulge mass ratio of ∼10−4, which is significantly smaller than that of classical bulges and elliptical galaxies.[23]

An article published in 2021, found out through observations by ESA's XMM-Newton and NASA's NuSTAR space telescopes, the black hole is found to emit out X-ray flares. Further analysis showed, there was short flashes of photons that are consistent with the re-emergence of emission. This proves they have reverberated off the far side of the black hole's accretion disk as light echoes, bended around and then magnified by its strong gravitational field.[24][25]

References edit

  1. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-05-20.
  2. ^ a b c d e f g h i "Host Galaxy of QSO I Zw 1". iopscience.iop.org. arXiv:astro-ph/9801061. doi:10.1086/305714. Retrieved 2024-05-20.
  3. ^ a b c "0050+124". quasar.square7.ch. Retrieved 2024-05-20.
  4. ^ Condon, J. J.; Hutchings, J. B.; Gower, A. C. (1985-09-01). "HI emission from quasar host galaxies". The Astronomical Journal. 90: 1642–1647. Bibcode:1985AJ.....90.1642C. doi:10.1086/113870. ISSN 0004-6256.
  5. ^ Buson, L. M.; Ulrich, M. -H. (1990-12-01). "The Ly-alpha and C IV lines in 10 low-redshift active galactic nuclei/quasars". Astronomy and Astrophysics. 240: 247. Bibcode:1990A&A...240..247B. ISSN 0004-6361.
  6. ^ Usher, P. D.; Shen, B. S. P.; Barrett, J. W. (1971-05-01). "I ZW 1: a Variable Compact Galaxy". The Astrophysical Journal. 165: 647. Bibcode:1971ApJ...165..647U. doi:10.1086/150930. ISSN 0004-637X.
  7. ^ Osterbrock, Donald E.; Martel, Andre (1993-09-01). "Spectroscopic Study of the CfA Sample of Seyfert Galaxies". The Astrophysical Journal. 414: 552. Bibcode:1993ApJ...414..552O. doi:10.1086/173102. ISSN 0004-637X.
  8. ^ Gallo, L. C.; Boller, Th; Brandt, W. N.; Fabian, A. C.; Vaughan, S. (2004-04-01). "I Zw 1 observed with XMM-Newton - Low-energy spectral complexity, iron lines, and hard X-ray flares". Astronomy & Astrophysics. 417 (1): 29–38. arXiv:astro-ph/0312298. Bibcode:2004A&A...417...29G. doi:10.1051/0004-6361:20034411. ISSN 0004-6361.
  9. ^ Panda, Swayamtrupta; Santos, Denimara Dias dos (2021-11-29), "Revisiting the spectral energy distribution of I Zw 1 under the CaFe Project", Acta Astrophysica Taurica, 3 (1): 27, arXiv:2111.01521, Bibcode:2022AcAT....3a..27P, doi:10.31059/aat.vol3.iss1.pp27-34
  10. ^ Kruper, J. S.; Urry, C. M.; Canizares, C. R. (1990-10-01). "Soft X-Ray Properties of Seyfert Galaxies. I. Spectra". The Astrophysical Journal Supplement Series. 74: 347. Bibcode:1990ApJS...74..347K. doi:10.1086/191503. ISSN 0067-0049.
  11. ^ Boller, T.; Brandt, W. N.; Fink, H. (1996-01-01). "Soft X-ray properties of narrow-line Seyfert 1 galaxies". Astronomy and Astrophysics. 305: 53. arXiv:astro-ph/9504093. Bibcode:1996A&A...305...53B. ISSN 0004-6361.
  12. ^ Véron-Cetty, M.-P.; Joly, M.; Véron, P. (2004-04-01). "The unusual emission line spectrum of I Zw 1". Astronomy & Astrophysics. 417 (2): 515–525. arXiv:astro-ph/0312654. Bibcode:2004A&A...417..515V. doi:10.1051/0004-6361:20035714. ISSN 0004-6361.
  13. ^ Scharwächter, J.; Eckart, A.; Pfalzner, S. (2001-01-01). "Merger Properties of the Narrow-line Seyfert 1 Galaxy I Zw 1". Astronomische Gesellschaft Meeting Abstracts. 18: MS 05 22. Bibcode:2001AGM....18S0522S.
  14. ^ Petrosian, Artashes; McLean, Brian; Allen, Ronald J.; MacKenty, John W. (2007-05-01). "Markarian Galaxies. I. The Optical Database and Atlas". The Astrophysical Journal Supplement Series. 170 (1): 33–70. Bibcode:2007ApJS..170...33P. doi:10.1086/511333. ISSN 0067-0049.
  15. ^ Bothun, G. D.; Heckman, T. M.; Schommer, R. A.; Balick, B. (1984-09-01). "CCD imaging and neutral hydrogen emission in I ZW 1 and other low-redshift QSOs/AGNs". The Astronomical Journal. 89: 1293–1299. Bibcode:1984AJ.....89.1293B. doi:10.1086/113627. ISSN 0004-6256.
  16. ^ Hutchings, J. B.; Crampton, D. (1990-01-01). "Images and Off-Nuclear Spectroscopy of QSOs". The Astronomical Journal. 99: 37. Bibcode:1990AJ.....99...37H. doi:10.1086/115309. ISSN 0004-6256.
  17. ^ Barvainis, Richard; Alloin, Danielle; Antonucci, Robert (1989-02-01). "Detection of Strong Carbon Monoxide Emission from the Host Galaxy of the Quasar I ZW 1". The Astrophysical Journal. 337: L69. Bibcode:1989ApJ...337L..69B. doi:10.1086/185380. ISSN 0004-637X.
  18. ^ a b Eckart, A.; van der Werf, P. P.; Hofmann, R.; Harris, A. I. (1994-04-01). "Interstellar Medium and Star Formation in the Nearby QSO I ZW 1". The Astrophysical Journal. 424: 627. Bibcode:1994ApJ...424..627E. doi:10.1086/173919. ISSN 0004-637X.
  19. ^ Guilloteau, S.; Delannoy, J.; Downes, D.; Greve, A.; Guelin, M.; Lucas, R.; Morris, D.; Radford, S. J. E.; Wink, J.; Cernicharo, J.; Forveille, T.; Garcia-Burillo, S.; Neri, R.; Blondel, J.; Perrigourad, A. (1992-09-01). "The IRAM interferometer on Plateau de Bure". Astronomy and Astrophysics. 262: 624. Bibcode:1992A&A...262..624G. ISSN 0004-6361.
  20. ^ Weitzel, L.; Krabbe, A.; Kroker, H.; Thatte, N.; Tacconi-Garman, L. E.; Cameron, M.; Genzel, R. (1996-11-01). "3D: The next generation near-infrared imaging spectrometer". Astronomy and Astrophysics Supplement Series. 119 (3): 531–546. Bibcode:1996A&AS..119..531W. doi:10.1051/aas:1996266. ISSN 0365-0138.
  21. ^ Buta, R.; Combes, F. (1996-01-01). "Galactic Rings". Fundamentals of Cosmic Physics. 17: 95–281. Bibcode:1996FCPh...17...95B.
  22. ^ Genzel, R.; Weitzel, L.; Tacconi-Garman, L. E.; Blietz, M.; Cameron, M.; Krabbe, A.; Lutz, D.; Sternberg, A. (1995-05-01). "Infrared Imaging and Spectroscopy of NGC 7469". The Astrophysical Journal. 444: 129. Bibcode:1995ApJ...444..129G. doi:10.1086/175588. ISSN 0004-637X.
  23. ^ Huang, Ying-Ke; Hu, Chen; Zhao, Yu-Lin; Zhang, Zhi-Xiang; Lu, Kai-Xing; Wang, Kai; Zhang, Yue; Du, Pu; Li, Yan-Rong; Bai, Jin-Ming; Ho, Luis C.; Bian, Wei-Hao; Yuan, Ye-Fei; Wang, Jian-Min (2019-05-08). "Reverberation Mapping of the Narrow-line Seyfert 1 Galaxy I Zwicky 1: Black Hole Mass". The Astrophysical Journal. 876 (2): 102. arXiv:1904.06146. Bibcode:2019ApJ...876..102H. doi:10.3847/1538-4357/ab16ef. ISSN 0004-637X.
  24. ^ Staff, News (2021-07-30). "Astronomers Detect Light Echoes Coming from Behind Supermassive Black Hole | Astronomy | Sci-News.com". Sci.News: Breaking Science News. Retrieved 2024-05-20. {{cite web}}: |first= has generic name (help)
  25. ^ Wilkins, D. R.; Gallo, L. C.; Costantini, E.; Brandt, W. N.; Blandford, R. D. (2021-07-29). "Light bending and X-ray echoes from behind a supermassive black hole". Nature. 595 (7869): 657–660. arXiv:2107.13555. doi:10.1038/s41586-021-03667-0. ISSN 0028-0836.
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