NGC 3081

Last updated
NGC 3081
Golden rings of star formation.jpg
Observation data (J2000 epoch)
Constellation Hydra
Right ascension 09h 59m 29.5s [1]
Declination −22° 49 35 [1]
Redshift 0.007976 ± 0.000010 [1]
Helio radial velocity 2,391 ± 3 km/s [1]
Distance 83 Mly (25.3 Mpc) [1]
Apparent magnitude  (V)13.5
Characteristics
Type (R_1)SAB(r)0/a [1]
Apparent size  (V)2.1 × 1.6 [1]
Notable features Seyfert galaxy
Other designations
IC 2529, ESO 499-G31, AM 0957-223, MCG -04-24-012, PGC 28876 [1]

NGC 3081 is a barred lenticular ring galaxy in the constellation of Hydra. NGC 3081 is located about 85 million light-years away from Earth, which means, given its apparent dimensions, that NGC 3081 is approximately 60,000 light-years across. It is a type II Seyfert galaxy, characterised by its bright nucleus. It was discovered by William Herschel on 21 December 1786.

Contents

NGC 3081 is seen nearly face-on. The galaxy's barred spiral centre is surrounded by a bright loop known as a resonance ring. This ring is full of bright clusters and bursts of new star formation, and frames the supermassive black hole thought to be lurking within NGC 3081—which glows brightly as it gobbles up infalling material. [2]

Characteristics

Active galactic nucleus

NGC 3081 is known to feature an active galaxy nucleus which leads to being categorised as a type II Seyfert galaxy. Even though NGC 3081 shows significant absorption, it is Compton thin. Also it does not show spectral variability on monthly timescales in X-rays. [3] In the nucleus of the galaxy is thought to exist a supermassive black hole whose mass upper limit is estimated to be between 8.5 and 37 million M, based on the intrinsic velocity dispersion as measured by the Hubble Space Telescope. [4]

Observations obtained with the GMOS integral field spectrograph on the Gemini North telescope show a gas flow is present in the inner ≈ 2 arcseconds (200 parsecs) of the galaxy, whose appearance is consistent with a bipolar outflow oriented along the north–south direction. Its outflow rate in ionized gas is estimated to be between 1.9 ×10−3M/year and 6.9 ×10−3M/year. There was also observed residual gas motion which is interpreted as gas following non-circular orbits in the barred potential, which may lead to gas inflow up to 1.3 ×10−2M/year. [5]

Resonance rings

NGC 3081 features four well defined rings; [6] a misaligned nuclear ring with angular radius 14", an aligned inner ring with angular radius 35", an outer ring with radius 90", and an outer pseudoring with radius 105". Each ring is a well-defined zone of active star formation, [7] while little or no star formation is observed between the rings. The rings lie at periodic orbits, known as resonances, certain positions where gravitational effects throughout the galaxy cause gas to pile up and accumulate in. These can be caused by the presence of a bar within the galaxy, as with NGC 3081, or by interactions with other nearby objects. It is not unusual for rings like this to be seen in barred galaxies, as the bars are very effective at gathering gas into these resonance regions, causing pile-ups which lead to active and very well-organised star formation. As external interactions could prevent the material from becoming sufficiently well organized in rings to trace the orbits so clearly, it is believed that NGC 3081 evolved in a relatively undisturbed manner. [8]

Within the nuclear ring has been obseverd a spiral structure with two arms. Some parts of the nuclear ring and discrete knots in the arms feature higher numbers of younger stars than the rest of the nuclear ring interior, which suggests that they are sites of recent or ongoing star formation. They also feature emission indicative of HII regions. [9] The inner ring, which is intrinsically elongated, features a gas cloud formed by the perturbation of a rotating bar at the location where the ring crosses the bar major axis, resulting in star formation. [10]

The outer ring features a dimpling near the bar axis, being aligned nearly perpendicular to it. The pseudoring is formed by two faint spiral arms beyond the outer ring that nearly close into another ring. The presence of both an outer ring and a pseudoring is rarely seen in barred galaxies. [6]

Bars

The galaxy features a complex double-barred structure as seen in optical and infrared wavelengths. The primary bar is weak and it is located within the inner ring. The secondary bar lies within the nuclear ring and is misaligned with the primary bar by 71 degrees. The secondary bar is also surrounded by a lens extending to the radius of the nuclear ring. In the residual image created by Laurikainen et al. the secondary bar shows an ansae-type morphology. [7]

Nearby galaxies

NGC 3081 is an isolated galaxy. [11] It is located within the same cloud of galaxies with NGC 3223, NGC 3001, NGC 3078, NGC 3089, NGC 3100, NGC 3275, NGC 3281, NGC 3347 and NGC 3449. [12]

See also

Related Research Articles

<span class="mw-page-title-main">Sombrero Galaxy</span> Galaxy in the constellation Virgo

The Sombrero Galaxy is a peculiar galaxy of unclear classification in the constellation borders of Virgo and Corvus, being about 9.55 megaparsecs from the Milky Way galaxy. It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. It has an isophotal diameter of approximately 29.09 to 32.32 kiloparsecs, making it slightly bigger in size than the Milky Way.

<span class="mw-page-title-main">NGC 2787</span> Galaxy in the constellation Ursa Major

NGC 2787 is a barred lenticular galaxy approximately 24 million light-years away in the northern constellation of Ursa Major. It was discovered on December 3, 1788 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "bright, pretty large, a little extended 90°, much brighter middle, mottled but not resolved, very small (faint) star involved to the southeast". The visible galaxy has an angular size of 2.5 × 1.5 arcminutes or 3.24 × 1.81 arcminutes and an apparent visual magnitude of 11.8.

<span class="mw-page-title-main">NGC 2841</span> Galaxy in the constellation Ursa Major

NGC 2841 is an unbarred spiral galaxy in the northern circumpolar constellation of Ursa Major. It was discovered on 9 March 1788 by German-born astronomer William Herschel. J. L. E. Dreyer, the author of the New General Catalogue, described it as, "very bright, large, very much extended 151°, very suddenly much brighter middle equal to 10th magnitude star". Initially thought to be about 30 million light-years distant, a 2001 Hubble Space Telescope survey of the galaxy's Cepheid variables determined its distance to be approximately 14.1 megaparsecs or 46 million light-years. The optical size of the galaxy is 8.1 × 3.5.

<span class="mw-page-title-main">NGC 5548</span> Type I Seyfert galaxy in the constellation Boötes

NGC 5548 is a Type I Seyfert galaxy with a bright, active nucleus. This activity is caused by matter flowing onto a 65 million solar mass (M) supermassive black hole at the core. Morphologically, this is an unbarred lenticular galaxy with tightly-wound spiral arms, while shell and tidal tail features suggest that it has undergone a cosmologically-recent merger or interaction event. NGC 5548 is approximately 245 million light years away and appears in the constellation Boötes. The apparent visual magnitude of NGC 5548 is approximately 13.3 in the V band.

<span class="mw-page-title-main">NGC 4314</span> Galaxy in the constellation Coma Berenices

NGC 4314 is a barred spiral galaxy approximately 53 million light-years away in the northern constellation of Coma Berenices. It is positioned around 3° to the north and slightly west of the star Gamma Comae Berenices and is visible in a small telescope. The galaxy was discovered by German-born astronomer William Herschel on March 13, 1785. It was labelled as peculiar by Allan Sandage in 1961 because of the unusual structure in the center of the bar. NGC 4314 is a member of the Coma I group of galaxies.

<span class="mw-page-title-main">NGC 1808</span> Galaxy in the constellation Columba

NGC 1808 is a barred spiral galaxy located in the southern constellation of Columba, about two degrees to the south and east of Gamma Caeli. It was discovered by Scottish astronomer James Dunlop, who described it as a "faint nebula". The galaxy is a member of the NGC 1808 group, which is part of the larger Dorado Group.

<span class="mw-page-title-main">NGC 1614</span> Galaxy in the constellation Eridanus

NGC 1614 is the New General Catalogue identifier for a spiral galaxy in the equatorial constellation of Eridanus. It was discovered on December 29, 1885 by American astronomer Lewis Swift, who described it in a shorthand notation as: pretty faint, small, round, a little brighter middle. The nebula was then catalogued by Danish-Irish astronomer J. L. E. Drayer in 1888. When direct photography became available, it was noted that this galaxy displayed some conspicuous peculiarities. American astronomer Halton Arp included it in his 1966 Atlas of Peculiar Galaxies. In 1971, Swiss astronomer Fritz Zwicky described it as a "blue post-eruptive galaxy, compact patchy core, spiral plumes, long blue jet SSW".

<span class="mw-page-title-main">NGC 3675</span> Galaxy in the constellation Ursa Major

NGC 3675 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 3675 is about 100,000 light years across. It was discovered by William Herschel in 1788.

<span class="mw-page-title-main">NGC 3941</span> Galaxy in the constellation Ursa Major

NGC 3941 is a barred lenticular galaxy located in the constellation Ursa Major. It is located at a distance of circa 40 million light years from Earth, which, given its apparent dimensions, means that NGC 3941 is about 40,000 light years across. It was discovered by William Herschel in 1787.

<span class="mw-page-title-main">NGC 2336</span> Galaxy in the constellation Camelopardalis

NGC 2336 is a barred spiral galaxy located in the constellation Camelopardalis. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 2336 is about 200,000 light years across. It was discovered by Wilhelm Tempel in 1876.

<span class="mw-page-title-main">NGC 7723</span> Galaxy in the constellation Aquarius

NGC 7723 is a barred spiral galaxy located in the constellation Aquarius. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 7723 is about 95,000 light years across. It was discovered by William Herschel on November 27, 1785. The galaxy is included in the Herschel 400 Catalogue. It lies 1.5 degrees north-northwest from Omega1 Aquarii. It can be seen with a 4-inch telescope under dark skies.

<span class="mw-page-title-main">NGC 7469</span> Galaxy located in the constellation Pegasus

NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.

<span class="mw-page-title-main">NGC 3367</span> Spiral galaxy in the constellation Leo

NGC 3367 is a barred spiral galaxy located in the constellation Leo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 3367 is about 85,000 light years across. It was discovered by William Herschel on March 19, 1784.

<span class="mw-page-title-main">NGC 985</span> Ring galaxy in the constellation Cetus

NGC 985 is a ring galaxy in the constellation of Cetus. It is located about 550 million light years away from Earth, which means, given its apparent dimensions, that NGC 985 is approximately 160,000 light years across. It was discovered by Francis Leavenworth in 1886. It is a type 1 Seyfert galaxy.

<span class="mw-page-title-main">NGC 6951</span> Galaxy in the constellation Cepheus

NGC 6951 is a barred spiral galaxy located in the constellation Cepheus. It is located at a distance of about 75 million light-years from Earth, which, given its apparent dimensions, means that NGC 6951 is about 100,000 light-years across. It was discovered by Jérôme Eugène Coggia in 1877 and independently by Lewis Swift in 1878.

<span class="mw-page-title-main">NGC 1386</span> Galaxy in the constellation Eridanus

NGC 1386 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 53 million light years from Earth, which, given its apparent dimensions, means that NGC 1386 is about 50,000 light years across. It is a Seyfert galaxy, the only one in Fornax Cluster.

<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 2974</span> Galaxy in the constellation Sextans

NGC 2974 is a lenticular galaxy located in the constellation Sextans. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 2974 is about 90,000 light years across. It was discovered by William Herschel on January 6, 1785. NGC 2974 is located in the sky about 2 and a half degrees south-south east of Iota Hydrae and more than 6 degrees northeast of Alphard. A 10th magnitude star lies next to the galaxy, thus making it a challenging object at low magnifications. NGC 2974 is part of the Herschel 400 Catalogue.

<span class="mw-page-title-main">NGC 1241</span> Galaxy in the constellation Eridanus

NGC 1241 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 150 million light years from Earth, which, given its apparent dimensions, means that NGC 1241 is about 140,000 light years across. It was discovered by William Herschel on January 10, 1785. It is classified as a Seyfert galaxy.

<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.

References

  1. 1 2 3 4 5 6 7 8 "NASA/IPAC Extragalactic Database". Results for NGC 3081. Retrieved 2017-04-18.
  2. "Golden rings of star formation". www.spacetelescope.org. 9 June 2014.
  3. Beckmann, V.; Gehrels, N.; Tueller, J. (September 2007). "The 1–200 keV X-Ray Spectrum of NGC 2992 and NGC 3081". The Astrophysical Journal. 666 (1): 122–127. arXiv: 0704.2698 . Bibcode:2007ApJ...666..122B. doi:10.1086/519486. S2CID   15403874.
  4. Beifiori, A.; Sarzi, M.; Corsini, E. M.; Bontà, E. Dalla; Pizzella, A.; Coccato, L.; Bertola, F. (10 February 2009). "Upper Limits on the Masses of 105 Supermassive Black Holes from Hubble Space Telescope/Space Telescope Imaging Spectrograph Archival Data". The Astrophysical Journal. 692 (1): 856–868. arXiv: 0809.5103 . Bibcode:2009ApJ...692..856B. doi:10.1088/0004-637X/692/1/856. S2CID   54903233.
  5. Schnorr-Müller, Allan; Storchi-Bergmann, Thaisa; Robinson, Andrew; Lena, Davide; Nagar, Neil M. (27 January 2016). "Feeding and feedback in NGC 3081". Monthly Notices of the Royal Astronomical Society. 457 (1): 972–985. arXiv: 1601.05432 . Bibcode:2016MNRAS.457..972S. doi:10.1093/mnras/stw037. S2CID   119118814.
  6. 1 2 Buta, R.; Purcell, Guy B. (February 1998). "NGC 3081: Surface Photometry and Kinematics of a Classic Resonance Ring Barred Galaxy". The Astronomical Journal. 115 (2): 484–501. Bibcode:1998AJ....115..484B. doi:10.1086/300225. S2CID   123499637.
  7. 1 2 Laurikainen, Eija; Salo, Heikki; Buta, Ronald; Knapen, Johan; Speltincx, Tom; Block, David (January 2006). "Morphology of 15 Southern Early?Type Disk Galaxies". The Astronomical Journal. 132 (6): 2634–2652. arXiv: astro-ph/0609343 . Bibcode:2006AJ....132.2634L. doi:10.1086/508810. S2CID   16856632.
  8. Buta, Ronald J.; Byrd, Gene G.; Freeman, Tarsh (April 2004). "A Hubble Space Telescope Study of Star Formation in the Inner Resonance Ring of NGC 3081". The Astronomical Journal. 127 (4): 1982–2001. Bibcode:2004AJ....127.1982B. doi:10.1086/382239. S2CID   119572372.
  9. Ferruit, Pierre; Wilson, Andrew S.; Mulchaey, John (May 2000). "Hubble Space Telescope WFPC2 Imaging of a Sample of Early-Type Seyfert Galaxies". The Astrophysical Journal Supplement Series. 128 (1): 139–169. Bibcode:2000ApJS..128..139F. doi: 10.1086/313379 .
  10. Byrd, Gene G.; Freeman, Tarsh; Buta, Ronald J. (March 2006). "The Inner Resonance Ring of NGC 3081. II. Star Formation, Bar Strength, Disk Surface Mass Density, and Mass-to-Light Ratio". The Astronomical Journal. 131 (3): 1377–1393. Bibcode:2006AJ....131.1377B. doi: 10.1086/499944 . S2CID   122862391.
  11. Karachentseva, V. E.; Mitronova, S. N.; Melnyk, O. V.; Karachentsev, I. D. (11 March 2010). "Catalog of isolated galaxies selected from the 2MASS survey". Astrophysical Bulletin. 65 (1): 1–17. arXiv: 1005.3191 . Bibcode:2010AstBu..65....1K. doi:10.1134/S1990341310010013. S2CID   118495973.
  12. Makarov, Dmitry; Karachentsev, Igor (21 April 2011). "Galaxy groups and clouds in the local (z~ 0.01) Universe". Monthly Notices of the Royal Astronomical Society. 412 (4): 2498–2520. arXiv: 1011.6277 . Bibcode:2011MNRAS.412.2498M. doi:10.1111/j.1365-2966.2010.18071.x. S2CID   119194025. Archived from the original on 31 January 2016. Retrieved 22 April 2018.