PKS 2004-447

Last updated
PKS 2004-447
Image of PKS 2004-447.jpg
The narrow-line Seyfert galaxy PKS 2004-447.
Observation data (J2000.0 epoch)
Constellation Sagittarius
Right ascension 20h 07m 55.184s
Declination −44° 34′ 44.277″
Redshift 0.240000
Heliocentric radial velocity 71,950 km/s
Distance 2.755 Gly
Apparent magnitude  (V)19.3
Apparent magnitude  (B)19.3
Characteristics
Type NLSy1
Other designations
LEDA 2830329, MRC J2004-447, 2FGL J2007.9-4430, OCARS 2004-447

PKS 2004-447 is a narrow-line Seyfert 1 galaxy [1] located in the constellation of Sagittarius. It has a redshift of (z) 0.24 [2] and is the radio-loudest gamma ray emitting AGN known in the southern hemisphere. [3] [4] It was first identified as an astronomical radio source during a very-long-baseline interferometry survey in 1989. [5] The radio spectrum appears to be powerful and compact, making it a compact steep spectrum source. [6] [7] The X-ray emission for this source is described by a simple power-law in the (0.5-10 KeV) energy range. [8]

PKS 2004-447 is classified as a blazar. [9] It is found variable on the electromagnetic spectrum and is a source of gamma ray activity. [10] [11] In October 2019, it was found to exhibit a gamma ray flare, [12] reaching a highest flux of (1.3 ± 0.2) x 10−6 photon cm−2 s−1 at gamma-ray energies (0.1-300 GeV). [13] A further study also showed during the post-flare in PKS 2004–447, there was the presence of Balmer, Paschen and Helium emission lines, with these lines vanishing within a period of 1.5 years. [12]

PKS 2004-447 has a core-jet structure with angular size measuring 40 mas. Its radio emission is found mainly dominated by the radio core, accounting for 42 percent of its total flux density at 1.4 GHz. There is a jet structure emerging from the core with a projected position angle measurement of -90°, which bends to -60° at 20 mas. This jet structure is further divided into two subcomponents enveloped completely from sight by the diffused emission. [14]

The host galaxy of PKS 2004-447 is a late-type barred disk galaxy with a stellar mass of ~ 7 x 1011 Mʘ, estimated from its K-band luminosity. It has a bulge showing a relatively low Sersic index of n ~ 1.2 with a bulge-to-total ratio of (B/T = 0.39 ± 0.02) for its J-band and (B/T = 0.44 ± 0.03) for its Ks-band. These values showed the bulge PKS 2004-447 is of pseudobulge morphology. [15] The host galaxy shows two faint spiral arms [16] and has an estimated black hole mass of 9 x 107 Mʘ. [15]

Related Research Articles

The Whole Earth Blazar Telescope (WEBT) is an international consortium of astronomers created in 1997, with the aim to study a particular category of Active Galactic Nuclei (AGN) called blazars, which are characterized by strong and fast brightness variability, on time scales down to hours or less.

<span class="mw-page-title-main">NGC 708</span> Galaxy in the constellation Andromeda

NGC 708 is an elliptical galaxy located 240 million light-years away in the constellation Andromeda and was discovered by astronomer William Herschel on September 21, 1786. It is classified as a cD galaxy and is the brightest member of Abell 262. NGC 708 is a weak FR I radio galaxy and is also classified as a type 2 Seyfert galaxy.

<span class="mw-page-title-main">NGC 2273</span> Galaxy in the constellation Lynx

NGC 2273 is a barred spiral galaxy located in the constellation Lynx. It is located at a distance of circa 95 million light years from Earth, which, given its apparent dimensions, means that NGC 2273 is about 100,000 light years across. It was discovered by Nils Dunér on September 15, 1867.

<span class="mw-page-title-main">NGC 7679</span> Galaxy in the constellation Pisces

NGC 7679 is a lenticular galaxy with a peculiar morphology in the constellation Pisces. It is located at a distance of about 200 million light years from Earth, which, given its apparent dimensions, means that NGC 7679 is about 60,000 light years across. It was discovered by Heinrich d'Arrest on September 23, 1864. The total infrared luminosity is 1011.05 L☉, and thus it is categorised as a luminous infrared galaxy. NGC 7679 is both a starburst galaxy and a Seyfert galaxy.

<span class="mw-page-title-main">AP Librae</span> Active galactic nucleus in the constellation Libra

AP Librae is a BL Lacertae object located at a distance of 700 million light years in the southern constellation of Libra. In the visual band it is one of the most active blazars known. AP Lib is surrounded by an extended source with a spectrum characteristic of a red-shifted giant elliptical galaxy. The derived visual magnitude of this region is 15.0, and it follows a radially decreasing brightness that is characteristic of an elliptical. Seven fainter galaxies are visible within an angular radius of 9′, suggesting it is the brightest member of a galactic cluster.

<span class="mw-page-title-main">NGC 4253</span> Galaxy in the constellation of Coma Berenices

NGC 4253 is a barred spiral galaxy located in the constellation Coma Berenices. It is located at a distance of about 185 million light years from Earth, which, given its apparent dimensions, means that NGC 4253 is about 65,000 light years across. It was discovered by William Herschel on February 3, 1788. It is a Seyfert galaxy.

<span class="mw-page-title-main">NGC 3786</span> Galaxy in the constellation Ursa Major

NGC 3786 is an intermediate spiral galaxy located 107.5 million light-years away in the northern constellation of Ursa Major. It was discovered by English astronomer John Herschel on April 10, 1831. This object appears to form a close pair with its peculiar neighbor to the north, NGC 3788. They show some indications of interaction, such as minor distortion of the disk or tidal features.

<span class="mw-page-title-main">IC 310</span> Lenticular galaxy in the constellation Perseus

IC 310 is a lenticular galaxy located in the constellation Perseus. It is located 265 million light-years from Earth, which means, given its apparent dimensions, it is about 117,000 light-years across. The galaxy was discovered by Edward D. Swift on November 3, 1888.

<span class="mw-page-title-main">PKS 0438-436</span> Quasar in the constellation Caelum

PKS 0438-436, also known as PKS J0440-4333, is a quasar located in constellation Caelum. With a high redshift of 2.86, the object is located 11.2 billion light-years from Earth and is classified as a blazar due to its flat-spectrum radio source, (in terms of the flux density as with α < 0.5 and its optical polarization.

<span class="mw-page-title-main">PG 0844+349</span> Galaxy in the constellation Lynx

PG 0844+349, also known as TON 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.

<span class="mw-page-title-main">PKS 1402+044</span> Quasar in the constellation of Virgo

PKS 1402+044 is a quasar located in the constellation of Virgo. It has a redshift of 3.207, estimating the object to be located 11.3 billion light-years away from Earth.

<span class="mw-page-title-main">PKS 0805-07</span> Quasar in the constellation of Monoceros

PKS 0805-07 also known as PMN J0808-0751 and 4FGL J0808.2-0751, is a quasar located in the constellation of Monoceros. With a redshift of 1.83, light has taken at least 10 billion light-years to reach Earth.

<span class="mw-page-title-main">MCG +08-11-011</span> Galaxy in the constellation Auriga

MCG +08-11-011 known as UGC 3374, is a galaxy located in the constellation of Auriga. It is located 401 million light years from Earth and is classified as a Seyfert galaxy.

<span class="mw-page-title-main">Markarian 1018</span> Galaxy in the constellation Cetus

Markarian 1018, also known as UGC 1597, is a lenticular galaxy with a peculiar structure located in the constellation Cetus. It is located at an approximate distance of 607 million light years from Earth and has an apparent dimensions of 0.99 by 0.52 arcmin. It is classified as a change looking Seyfert galaxy and galaxy merger.

<span class="mw-page-title-main">1H 0323+342</span> Narrow-line Seyfert galaxy in the constellation Perseus

1H 0323+342 known as 2MASX J032441.19+341045.9, is a galaxy located in the constellation of Perseus. It is located 831 million light years from Earth. It is classified a gamma-ray emitting narrow-line Seyfert galaxy, the nearest known example of this subtype.

<span class="mw-page-title-main">PKS 1830-211</span> Quasar in the constellation Sagittarius

PKS 1830-211 is a gravitationally-lensed blazar in the southern constellation of Sagittarius, one of the most powerful such objects known. It has a high redshift (z) of 2.507, an indicator of its significant distance. This flat-spectrum radio quasar (FSRQ) is one of the brightest extraterrestrial radio sources. In visible light, identification of this object is hampered by the galactic plane and an M-type star that lies near the line of sight.

<span class="mw-page-title-main">RX J1633.3+4718</span> Narrow-line Seyfert galaxy located in the constellation Hercules

RX J1633.3+4718 known as RXS J16333+4718 according to VLBI Network observations, is a narrow-line Seyfert 1 galaxy, located in the constellation of Hercules. It has a redshift of (z) 0.116 and is located 1.75 billion light years from Earth. The first known reference to this galaxy comes from a radio source which was identified in 1995 in the IRAS catalogue as F16319+4725.

<span class="mw-page-title-main">NRAO 530</span> Flat spectrum radio quasar in the constellation Serpens

NRAO 530 or PKS 1730-13 is a flat-spectrum radio quasar located in the southern constellation of Serpens. It has a redshift of 0.902. and was first discovered by two astronomers, W.J. Welch and Hyron Spinrad in 1973. It is classified as a blazar because of its optical variability across the electromagnetic spectrum in radio, gamma ray and X-ray bands. This quasar is also further categorized an OVV quasar.

<span class="mw-page-title-main">PKS 1424-418</span> Blazar in the constellation Centaurus

PKS 1424-418 is a blazar located in the constellation of Centaurus. It has a redshift of 1.522 and was first discovered in 1971 by astronomer Keith Peter Tritton who identified the object as ultraviolet-excessive. This object is also highly polarized with a compact radio source. The radio spectrum of this source appears flat, making it a flat-spectrum radio quasar.

References

  1. ↑ "Fermi LAT detection of a GeV flare from the radio-loud narrow-line Seyfert 1 Galaxy PKS 2004-447". The Astronomer's Telegram. Retrieved 2024-11-04.
  2. ↑ Oshlack, A. Y. K. N.; Webster, R. L.; Whiting, M. T. (2001-09-10). "A Very Radio Loud Narrow-Line Seyfert 1: PKS 2004−447". The Astrophysical Journal. 558 (2): 578–582. arXiv: astro-ph/0105213 . Bibcode:2001ApJ...558..578O. doi:10.1086/322299. ISSN   0004-637X.
  3. ↑ Schulz, R.; Kreikenbohm, A.; Kadler, M.; Ojha, R.; Ros, E.; Stevens, J.; Edwards, P. G.; Carpenter, B.; Elsässer, D.; Gehrels, N.; Großberger, C.; Hase, H.; Horiuchi, S.; Lovell, J. E. J.; Mannheim, K. (2016-04-01). "The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004−447 - II. The radio view". Astronomy & Astrophysics. 588: A146. arXiv: 1511.02631 . Bibcode:2016A&A...588A.146S. doi:10.1051/0004-6361/201527404. ISSN   0004-6361.
  4. ↑ Kreikenbohm, A.; Schulz, R.; Kadler, M.; Wilms, J.; Markowitz, A.; Chang, C. S.; Carpenter, B.; Elsässer, D.; Gehrels, N.; Mannheim, K.; Müller, C.; Ojha, R.; Ros, E.; Trüstedt, J. (2016-01-01). "The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004−447 - I. The X-ray View". Astronomy & Astrophysics. 585: A91. arXiv: 1509.03735 . Bibcode:2016A&A...585A..91K. doi:10.1051/0004-6361/201424818. ISSN   0004-6361.
  5. ↑ Jauncey, David L.; Savage, Ann; Morabito, David D.; Preston, Robert A.; Nicolson, George D.; Tzioumis, Anastasios K. (July 1989). "Optical identifications of southern compact radio sources". The Astronomical Journal. 98: 54. Bibcode:1989AJ.....98...54J. doi:10.1086/115127. ISSN   0004-6256.
  6. ↑ Gallo, L. C.; Edwards, P. G.; Ferrero, E.; Kataoka, J.; Lewis, D. R.; Ellingsen, S. P.; Misanovic, Z.; Welsh, W. F.; Whiting, M.; Boller, T.; Brinkmann, W.; Greenhill, J.; Oshlack, A. (2006-07-21). "The spectral energy distribution of PKS 2004-447: a compact steep-spectrum source and possible radio-loud narrow-line Seyfert 1 galaxy". Monthly Notices of the Royal Astronomical Society. 370 (1): 245–254. arXiv: astro-ph/0604480 . Bibcode:2006MNRAS.370..245G. doi: 10.1111/j.1365-2966.2006.10482.x . ISSN   0035-8711.
  7. ↑ Berton, M.; Peluso, G.; Marziani, P.; Komossa, S.; Foschini, L.; Ciroi, S.; Chen, S.; Congiu, E.; Gallo, L. C.; Björklund, I.; Crepaldi, L.; Di Mille, F.; Järvelä, E.; Kotilainen, J.; Kreikenbohm, A. (October 2021). "Hunting for the nature of the enigmatic narrow-line Seyfert 1 galaxy PKS 2004-447" (PDF). Astronomy & Astrophysics. 654: A125. arXiv: 2106.12536 . Bibcode:2021A&A...654A.125B. doi:10.1051/0004-6361/202141409. ISSN   0004-6361.
  8. ↑ Kreikenbohm, A.; Schulz, R.; Kadler, M.; Wilms, J.; Markowitz, A.; Chang, C. S.; Carpenter, B.; Elsässer, D.; Gehrels, N.; Mannheim, K.; Müller, C.; Ojha, R.; Ros, E.; Trüstedt, J. (2015-12-23). "The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004−447" (PDF). Astronomy & Astrophysics. 585: A91. Bibcode:2016A&A...585A..91K. doi:10.1051/0004-6361/201424818. ISSN   0004-6361.
  9. ↑ D'Abrusco, R.; Massaro, F.; Ajello, M.; Grindlay, J. E.; Smith, Howard A.; Tosti, G. (2012-03-06). "Infrared Colors Of The Gamma-Ray-Detected Blazars". The Astrophysical Journal. 748 (1): 68. arXiv: 1203.0568 . Bibcode:2012ApJ...748...68D. doi:10.1088/0004-637x/748/1/68. ISSN   0004-637X.
  10. ↑ Berton, M.; Ciroi, S.; Congiu, E.; Chen, S.; Crepaldi, L.; Di Mille, F.; Foschini, L.; Jarvela, E.; Komossa, S.; Kotilainen, J.; Lahteenmaki, A.; Vietri, A. (2019-11-01). "Spectroscopic observations of the flaring gamma-ray narrow-line Seyfert 1 PKS 2004-447". The Astronomer's Telegram. 13259: 1. Bibcode:2019ATel13259....1B.
  11. ↑ "Swift follow-up of the flaring NLSy1 PKS 2004-447". The Astronomer's Telegram. Retrieved 2024-11-04.
  12. 1 2 Hon, W.; Berton, M.; Sani, E.; Webster, R.; Wolf, C.; Rojas, A. F.; Marziani, P.; Kotilainen, J.; Congiu, E. (April 2023). "A redshifted excess in the broad emission lines after the flare of the γ-ray narrow-line Seyfert 1 PKS 2004−447" (PDF). Astronomy & Astrophysics. 672: L14. doi:10.1051/0004-6361/202245184. ISSN   0004-6361.
  13. ↑ Gokus, A.; Paliya, V. S.; Wagner, S. M.; Buson, S.; D’Ammando, F.; Edwards, P. G.; Kadler, M.; Meyer, M.; Ojha, R.; Stevens, J.; Wilms, J. (2021-05-01). "The first GeV flare of the radio-loud narrow-line Seyfert 1 galaxy PKS 2004–447". Astronomy & Astrophysics. 649: A77. arXiv: 2102.11633 . Bibcode:2021A&A...649A..77G. doi:10.1051/0004-6361/202039378. ISSN   0004-6361.
  14. ↑ Orienti, M.; D'Ammando, F.; Larsson, J.; Finke, J.; Giroletti, M.; Dallacasa, D.; Isacsson, T.; Stoby Hoglund, J. (2015-09-14). "Investigating powerful jets in radio-loud narrow-line Seyfert 1s". Monthly Notices of the Royal Astronomical Society. 453 (4): 4038–4051. doi: 10.1093/mnras/stv1845 . ISSN   0035-8711.
  15. 1 2 Kotilainen, Jari K.; León-Tavares, Jonathan; Olguín-Iglesias, Alejandro; Baes, Maarten; Anórve, Christopher; Chavushyan, Vahram; Carrasco, Luis (2016-11-29). "Discovery Of a Pseudobuldge Galaxy Launching Powerful Relativistic Jets". The Astrophysical Journal. 832 (2): 157. arXiv: 1609.02417 . Bibcode:2016ApJ...832..157K. doi: 10.3847/0004-637x/832/2/157 . ISSN   0004-637X.
  16. ↑ Olguín-Iglesias, Alejandro; Kotilainen, Jari; Chavushyan, Vahram (2019-12-23). "The disc-like host galaxies of radio-loud narrow-line Seyfert 1s". Monthly Notices of the Royal Astronomical Society. 492 (1): 1450–1464. doi: 10.1093/mnras/stz3549 . ISSN   0035-8711.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.