Markarian 817

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Markarian 817
Markarian 817 (captured by the Hubble Space Telescope).jpg
Mrk 817 taken by Hubble Space Telescope
Observation data (J2000 epoch)
Constellation Draco
Right ascension 14h 36m 22.068s
Declination +58d 47m 39.38s
Redshift 0.031328
Heliocentric radial velocity 9,392 km/s
Distance 456 Mly (140 Mpc)
Apparent magnitude  (V)14.6
Characteristics
Type SBc, Sy1.5
Apparent size  (V)0.6' x 0.6'
Notable features Seyfert galaxy
Other designations
UGC 9412, SBS 1434+590, CGCG 296-015, IRAS 14349+5900, PGC 52202

Markarian 817 is a barred spiral galaxy located in the constellation Draco. It is located 456 million light-years from Earth, which, given its apparent dimensions, means that Markarian 817 is about 80,000 light-years across. [1] It is a Seyfert galaxy.

Contents

Features

The nucleus of Markarian 817 is found to be active. It is classified as a Seyfert 1.5 [2] or Seyfert 1.2 galaxy by the recent work done, according to Koss et al. 2017. [3] The nucleus sits in a barred spiral galaxy, close to face-on and not typical for optically selected unobscured Seyferts. [4] There is evidence of dust along the galaxy's bar according to the Hubble image. [5]

A study conducted in February 2011, shows that the active core is not fixed as it shows strong variabilities in X-rays and ultraviolet rays (UV). The X-ray luminosity varies by a factor of ~40 over 20 years, while the UV continuum/emission lines vary at the most by a factor of ~2.3 over the past 30 years. [6] [7]

A 2021 study shows that the X-ray spectrum in Markarian 817 is highly absorbed and there are new blueshifted, broad, and narrow UV absorption lines, suggesting a dust-free, ionized obscurer that is located in the inner broad-line region, partially covering the central source. [8] During the first 55 days, scientists observed there is a de-coupling of the UV continuum and the UV broad emission line variability. The next 42 days of the campaign showed the correlation recovering, as Markarian 817 entered the less obscured state. The short C IV and Lyα lags suggest that the accretion disk extends beyond the UV broad-line region. [8]

Markarian 817 has become a notable target of the AGN STORM 2 project, in which a group of astronomers lead by Edward M. Cackett from the Wayne State University in Detroit, monitored the galaxy with the Neil Gehrels Swift Observatory for 15 months, during which they obtained observations in X-rays and six ultraviolet/optical filters to shed more light on Markarian 817. [9]

Further observations done in 2022 showed that the source flux in Markarian 817 has declined compared to that recorded at a prior point during the 19-year mission. From the deep XMM Newton and NuSTAR observations, the spectra presents a complex X-ray wind which consists of neutral and ionized absorption zones. Three velocity components are detected from the part of the structured ultra-fast outflow with v/c = 0.043 (+0.007,-0.003), v/c = 0.079 (+0.003,-0.0008), and v/c = 0.074 (+0.004,-0.005). [10] These suggest that the wind likely arises at radii that are smaller compared to the optical broad line region. [10]

Black hole

An artist's impression of ultra-fast winds blasting out from the center of Markarian 817. Strong black hole winds reshape a galaxy ESA25463575.tiff
An artist's impression of ultra-fast winds blasting out from the center of Markarian 817.

The central black hole in Markarian 817 has an estimated solar mass of (4.9 +/- 0.8) E+7 according to Peterson et al. 2004. [11] Such winds tend to move at many millions of kilometers per hour, thus cleaning up interstellar gas from their region of space. This cuts off the rate of production of new stars being formed in Markarian 817, leaving very little matter to feed the accretion disk. [12] This suggests that the black hole is experiencing a "temper tantrum" and is responsible for shaping its host galaxy. [13]

In an article in which Markarian 817 and another Seyfert galaxy NGC 7469 is studied, it is revealed both AGNs displayed time lags in the broad emission line, including H, H, He~{\sc ii} and He~{\sc i} and also the Fe~{\sc ii} for Markarian 817 with respect to the varying continuum at 5100~Å. [14] From the relationship of line widths and time lags, both galaxies showed that the broad-line regions (BLR) dynamics are consistent with the viral predication. Data provided from Markarian 817 showed almost the same kinetic structures, in which the time lags in the red wing is larger compared to the time lags in the blue wing. This indicates the BLR of Keplerian motion seemly has outflowing components during the monitoring period. [14]

See also

Related Research Articles

An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such excess, non-stellar emissions have been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy.

<span class="mw-page-title-main">Ionization cone</span> Astronomical phenomenon

Ionization cones are cones of ionized material extending from active galactic nuclei, predominantly observed in type II Seyfert galaxies. They are detected through their emission of electromagnetic radiation in the visible and infrared parts of the spectrum. The main method of observation is through spectroscopy, using spectral line analysis to measure the shape of the ionized region and the condition of the material such as temperature, density, composition, and degree of ionization.

<span class="mw-page-title-main">Hanny's Voorwerp</span> Astronomical object appearing as a bright blob, discovered by Hanny van Arkel

Hanny's Voorwerp is a type of astronomical object called a quasar ionization echo. It was discovered in 2007 by Dutch schoolteacher Hanny van Arkel while she was participating as a volunteer in the Galaxy Zoo project, part of the Zooniverse group of citizen science websites. Photographically, it appears as a bright blob close to spiral galaxy IC 2497 in the constellation Leo Minor.

<span class="mw-page-title-main">Markarian 231</span> Seyfert galaxy in the constellation Ursa Major

Markarian 231 is a Type-1 Seyfert galaxy that was discovered in 1969 as part of a search of galaxies with strong ultraviolet radiation. It contains the nearest known quasar. Markarian 231 is located about 581 million light years away from Earth, in the constellation of Ursa Major.

<span class="mw-page-title-main">Tidal disruption event</span> Pulling apart of a star by tidal forces when it gets too close to a supermassive black hole

A tidal disruption event (TDE) is a transient astronomical source produced when a star passes so close to a supermassive black hole (SMBH) that it is pulled apart by the black hole's tidal force. The star undergoes spaghettification, producing a tidal stream of material that loops around the black hole. Some portion of the stellar material is captured into orbit, forming an accretion disk around the black hole, which emits electromagnetic radiation. In a small fraction of TDEs, a relativistic jet is also produced. As the material in the disk is gradually consumed by the black hole, the TDE fades over several months or years.

<span class="mw-page-title-main">NGC 6814</span> Galaxy in the constellation Aquila

NGC 6814 is an intermediate spiral galaxy in constellation Aquila. It is located at a distance of about 75 million light years from Earth, which, given its apparent dimensions, means that NGC 6814 is about 85,000 light years across. NGC 6814 has an extremely bright nucleus and is a type 1.5 Seyfert galaxy. The galaxy is also a highly variable source of X-ray radiation. The ultraviolet and optical emission also varies, although more smoothly, with time lag of two days. The cause of the lag and the smoothing of light curves is considered to be the reprocessing of the X-rays in the accretion disk. The cause of the active galactic nucleus is suspected to be a supermassive black hole with a mass about 18 million times that of the Sun. Many regions of ionised gas are studded along the dusty spiral arms.

<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 931</span> Galaxy in the constellation Triangulum

NGC 931 is a spiral galaxy located in the constellation Triangulum. It is located at a distance of circa 200 million light-years from Earth, which, given its apparent dimensions, means that NGC 931 is about 200,000 light years across. It was discovered by Heinrich d'Arrest on September 26, 1865. It is classified as a Seyfert galaxy.

Misty C. Bentz is an American astrophysicist and Professor of Physics and Astronomy at Georgia State University. She is best known for her work on supermassive black hole mass measurements and black hole scaling relationships.

<span class="mw-page-title-main">NGC 5728</span> Spiral galaxy in the constellation Libra

NGC 5728 is an active barred spiral galaxy located 146 million light years away in the southern constellation of Libra. It was discovered on May 7, 1787 by William Herschel. The designation comes from the New General Catalogue of J. L. E. Dreyer, published in 1888. It has an apparent visual magnitude of 13.40 and spans an angle of 3.4 arcminutes. The galaxy shows a red shift of 0.00935 and has a heliocentric radial velocity of 2,803 km/s. It has an estimated mass of 72 billion times the mass of the Sun and stretches around 30 kpc across.

<span class="mw-page-title-main">NGC 2617</span> Galaxy in the constellation Hydra

NGC 2617 is a Seyfert galaxy in the equatorial constellation of Hydra. It was discovered on February 12, 1885, by French astronomer Édouard Stephan. In 1888, Danish astronomer J. L. E. Dreyer described it as "extremely faint, very small, 2 very faint stars involved". It is located at an estimated distance of 202 million light years. In the infrared, the galaxy has an angular size of 0.693 by 0.652 arcminutes.

<span class="mw-page-title-main">NGC 3516</span> Galaxy in the constellation of Ursa Major

NGC 3516 is a barred lenticular galaxy in the constellation of Ursa Major. NGC 3516 is located about 150 million light years away from Earth, which means, given its apparent dimensions, that NGC 3516 is approximately 100,000 light years across. It was discovered by William Herschel on April 3, 1785.

<span class="mw-page-title-main">Markarian 590</span> Galaxy in the constellation of Cetus

Markarian 590, also known as NGC 863, NGC 866, and NGC 885, is a spiral galaxy located in the constellation Cetus. It is located at a distance of about 300 million light years from Earth, which, given its apparent dimensions, means that NGC 863 is about 110,000 light years across. It is a change looking Seyfert galaxy.

<span class="mw-page-title-main">Markarian 273</span> Galaxy in the constellation of Ursa Major

Markarian 273 is a galaxy merger located in the constellation Ursa Major. It is located at a distance of about 500 million light years from Earth, which, given its apparent dimensions, means that Markarian 273 is about 130,000 light years across. It is an ultraluminous infrared galaxy and a Seyfert galaxy.

<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">3C 120</span> Galaxy in the constellation Taurus

3C 120, also known as Markarian 1506, is an active galaxy located in the constellation of Taurus, at a distance of about 420 million light years. It has been categorised as a type I Seyfert galaxy and a broad-line radio galaxy. 3C 120 has been found to be a variable source in all wavelengths and hosts a superluminal jet.

<span class="mw-page-title-main">NGC 5273</span> Galaxy in the constellation Canes Venatici

NGC 5273 is a lenticular galaxy located 54 million light-years away in the northern constellation of Canes Venatici. This galaxy was discovered by William Herschel on May 1, 1785. It is positioned 1+1⁄4° to the southeast of the star 25 Canum Venaticorum.

<span class="mw-page-title-main">Extended emission-line region</span> Interstellar clouds

An extended emission-line region (EELR) is a giant interstellar cloud ionized by the radiation of an active galactic nucleus (AGN) inside a galaxy or photons produced by the shocks associated with the radio jets. An EELR can appear as a resolved cloud in relative nearby galaxies and as narrow emission lines in more distant galaxies.

<span class="mw-page-title-main">IRAS 05189-2524</span>

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<span class="mw-page-title-main">IRAS F11119+3257</span>

IRAS F11119+3257 or simply as F11119+3257, is a galaxy located in constellation Ursa Major. With a redshift of 0.187580, it has a light travel time distance of 2.5 billion light-years and is considered an ultraluminous infrared galaxy (ULIRG).

References

  1. ↑ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-05-12.
  2. ↑ IIic, D.; Popovic, L C; Bon, E.; Mediavilla, E. G.; Chavushyan, V. H. "Complex emission line region of Mrk 817". academic.oup.com. Retrieved 2024-05-12.
  3. ↑ Koss, Michael; Trakhtenbrot, Benny; Ricci, Claudio; Lamperti, Isabella; Oh, Kyuseok; Berney, Simon; Schawinski, Kevin; Baloković, Mislav; Baronchelli, Linda; Crenshaw, D. Michael; Fischer, Travis; Gehrels, Neil; Harrison, Fiona; Hashimoto, Yasuhiro; Hogg, Drew (2017-11-01). "BAT AGN Spectroscopic Survey. I. Spectral Measurements, Derived Quantities, and AGN Demographics". The Astrophysical Journal. 850 (1): 74. arXiv: 1707.08123 . Bibcode:2017ApJ...850...74K. doi: 10.3847/1538-4357/aa8ec9 . ISSN   0004-637X.
  4. ↑ McLeod, K. K.; Rieke, G. H. (1995-03-01). "Near-Infrared Imaging of CfA Seyfert Galaxies". The Astrophysical Journal. 441: 96. Bibcode:1995ApJ...441...96M. doi:10.1086/175339. ISSN   0004-637X.
  5. ↑ Pogge, Richard W.; Martini, Paul (2002-04-20). "Hubble Space TelescopeImaging of the Circumnuclear Environments of the CfA Seyfert Galaxies: Nuclear Spirals and Fueling". The Astrophysical Journal. 569 (2): 624–640. arXiv: astro-ph/0201185 . Bibcode:2002ApJ...569..624P. doi:10.1086/339400. ISSN   0004-637X.
  6. ↑ Winter, Lisa M.; Danforth, Charles; Vasudevan, Ranjan; Brandt, W. N.; Scott, Jennifer; Froning, Cynthia; Keeney, Brian; Shull, J. Michael; Penton, Steve; Mushotzky, Richard; Schneider, Donald P.; Arav, Nahum (2011-02-01). "Ultraviolet and X-ray Variability of the Seyfert 1.5 Galaxy Markarian 817". The Astrophysical Journal. 728 (1): 28. arXiv: 1012.0592 . Bibcode:2011ApJ...728...28W. doi:10.1088/0004-637X/728/1/28. ISSN   0004-637X.
  7. ↑ Morales, Anthony M.; Miller, Jon M.; Cackett, Edward M.; Reynolds, Mark T.; Zoghbi, Abderahmen (2019-01-01). "X-Ray and UV Monitoring of the Seyfert 1.5 Galaxy Markarian 817". The Astrophysical Journal. 870 (1): 54. arXiv: 1812.06945 . Bibcode:2019ApJ...870...54M. doi: 10.3847/1538-4357/aaeff9 . ISSN   0004-637X.
  8. 1 2 Kara, Erin; Mehdipour, Missagh; Kriss, Gerard A.; Cackett, Edward M.; Arav, Nahum; Barth, Aaron J.; Byun, Doyee; Brotherton, Michael S.; De Rosa, Gisella; Gelbord, Jonathan; Hernández Santisteban, Juan V.; Hu, Chen; Kaastra, Jelle; Landt, Hermine; Li, Yan-Rong (2021-12-01). "AGN STORM 2. I. First results: A Change in the Weather of Mrk 817". The Astrophysical Journal. 922 (2): 151. arXiv: 2105.05840 . Bibcode:2021ApJ...922..151K. doi: 10.3847/1538-4357/ac2159 . ISSN   0004-637X.
  9. ↑ Nowakowski, Tomasz; Phys.org. "Observations shed more light on the properties of the galaxy Markarian 817". phys.org. Retrieved 2024-05-12.
  10. 1 2 Zak, Miranda K.; Miller, Jon M.; Behar, Ehud; Brandt, William N.; Brenneman, Laura; Draghis, Paul A.; Kammoun, Elias; Koss, Michael J.; Reynolds, Mark T. (2023-12-11), "Fierce Feedback in an Obscured, Sub-Eddington State of the Seyfert 1.2 Markarian 817", The Astrophysical Journal, 962 (1): L1, arXiv: 2312.06487 , Bibcode:2024ApJ...962L...1Z, doi: 10.3847/2041-8213/ad1407 , retrieved 2024-05-12
  11. ↑ Zak, M. K.; Miller, J. M.; Reynolds, M. T.; Gediman, B.; Han, C.; Hemrattaphan, Y. (2022-04-01). "Recent Swift Monitoring of Mrk 817 Reveals an Extremely Low Flux State". The Astronomer's Telegram. 15316: 1. Bibcode:2022ATel15316....1Z.
  12. ↑ "Strong black hole winds reshape a galaxy". www.esa.int. Retrieved 2024-05-12.
  13. ↑ Joanna Thompson (2024-02-07). "Star-killing 'black hole wind' spotted in a distant galaxy could explain a major mystery at the Milky Way's center". livescience.com. Retrieved 2024-05-12.
  14. 1 2 Lu, Kai-Xing; Wang, Jian-Guo; Zhang, Zhi-Xiang; Huang, Ying-Ke; Xu, Liang; Xin, Yu-Xin; Yu, Xiao-Guang; Ding, Xu; Wang, De-Qing; Feng, Hai-Cheng (2021-09-01). "Reverberation Mapping Measurements of Black Hole Masses and Broad-Line Region Kinematics in Mrk 817 and NGC 7469". The Astrophysical Journal. 918 (2): 50. arXiv: 2106.10589 . Bibcode:2021ApJ...918...50L. doi: 10.3847/1538-4357/ac0c78 . ISSN   0004-637X.
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