| 词条 | NGC 3621 |
| 释义 |
| name = NGC 3621 | image = NGC 3621.jpg | image_size = 300px | caption = NGC 3621 taken by the Wide Field Imager (WFI) at ESO’s La Silla Observatory | credit = ESO and Joe DePasquale | epoch = J2000 | pronounce = | constellation name = Hydra | ra = {{RA|11|18|16.52}}[1] | dec = {{DEC|–32|48|50.7}}[1] | z = {{nowrap|0.002435 ± 0.000007}}[3] | h_radial_v = +727[4] km/s | gal_v = | dist_ly = {{nowrap|21.7 million light years (6.64 Mpc)}}[5] | group_cluster = | type = SA(s)d[1] | mass = 2 × 1010[1] | stars = | appmag_v = 10.0 | size_v = | notes = | names = | references = }}NGC 3621 is a field spiral galaxy about {{convert|22|Mly|Mpc|abbr=on|lk=on}} away[5][1] in the equatorial constellation of Hydra. It is comparatively bright and can be well seen in moderate-sized telescopes. The galaxy is around {{Convert|93000|ly|pc|abbr=on}} across and is inclined at an angle of 25° from being viewed edge on. It shines with a luminosity equal to 13 billion times that of the Sun.[10] The morphological classification is SA(s)d,[1] which indicates this is an ordinary spiral with loosely wound arms. There is no evidence for a bulge.[13] Although it appears to be isolated, NGC 3621 belongs to the Leo spur.[10] This galaxy has an active nucleus that matches a Seyfert 2 optical spectrum, suggesting that a low mass supermassive black hole is present at the core. Based upon the motion of stars in the nucleus, this object may have a mass of up to three million times the mass of the Sun.[13] References1. ^{{Cite journal |title= The structure of nearby groups of galaxies - Quantitative membership probabilities |author= Materne, J. |date= April 1979 |journal= Astronomy and Astrophysics |volume= 74 |number= 2 |pages= 235–243 |bibcode= 1979A&A....74..235M }} [2][3][4][5][6][7]2. ^1 2 {{Citation | first1 = Stephen James | last1 = O'Meara | title = Deep-Sky Companions: Southern Gems | publisher = Cambridge University Press | page = 203 | date = 2013 | isbn = 978-1107015012 | url = https://books.google.com/books?id=S5QIEKns33sC&pg=PA203 | postscript= .| bibcode = 2013dcsg.book.....O }} 3. ^1 2 {{Citation | last1 = Tully | first1 = R. Brent | last2 = Shaya | first2 = Edward J. | last3 = Karachentsev | first3 = Igor D. | last4 = Courtois | first4 = Hélène M. | last5 = Kocevski | first5 = Dale D. | last6 = Rizzi | first6 = Luca | last7 = Peel | first7 = Alan | display-authors = 1 | title = Our Peculiar Motion Away from the Local Void | journal = The Astrophysical Journal | volume = 676 | issue = 1 | pages = 184–205 |date=March 2008 | doi = 10.1086/527428 | bibcode = 2008ApJ...676..184T | arxiv = 0705.4139 | postscript= .}} 4. ^1 {{Citation | last1 = Tully | first1 = R. Brent | last2 = Shaya | first2 = Edward J. | last3 = Karachentsev | first3 = Igor D. | last4 = Courtois | first4 = Hélène M. | last5 = Kocevski | first5 = Dale D. | last6 = Rizzi | first6 = Luca | last7 = Peel | first7 = Alan | display-authors = 1 | title = Recalibration of the H–0.5 magnitudes of spiral galaxies | journal = Astrophysical Journal Supplement Series | volume = 96 | issue = 1 | pages = 123–157 |date=January 1995 | doi = 10.1086/192115 | bibcode = 1995ApJS...96..123T | arxiv = astro-ph/9405047 | postscript= .}} 5. ^1 {{citation | last1=Koribalski | first1=B. S. | last2=Staveley-Smith | first2=L. | last3=Kilborn | first3=V. A. | last4=Ryder | first4=S. D. | last5=Kraan-Korteweg | first5=R. C. | last6=Ryan-Weber | first6=E. V. | last7=Ekers | first7=R. D. | last8=Jerjen | first8=H. | last9=Henning | first9=P. A. | last10=Putman | first10=M. E. | last11=Zwaan | first11=M. A. | last12=de Blok | first12=W. J. G. | last13=Calabretta | first13=M. R. | last14=Disney | first14=M. J. | last15=Minchin | first15=R. F. | last16=Bhathal | first16=R. | last17=Boyce | first17=P. J. | last18=Drinkwater | first18=M. J. | last19=Freeman | first19=K. C. | last20=Gibson | first20=B. K. | last21=Green | first21=A. J. | last22=Haynes | first22=R. F. | last23=Juraszek | first23=S. | last24=Kesteven | first24=M. J. | last25=Knezek | first25=P. M. | last26=Mader | first26=S. | last27=Marquarding | first27=M. | last28=Meyer | first28=M. | last29=Mould | first29=J. R. | last30=Oosterloo | first30=T. | last31=O'Brien | first31=J. | last32=Price | first32=R. M. | last33=Sadler | first33=E. M. | last34=Schröder | first34=A. | last35=Stewart | first35=I. M. | last36=Stootman | first36=F. | last37=Waugh | first37=M. | last38=Warren | first38=B. E. | last39=Webster | first39=R. L. | last40=Wright | first40=A. E. | title=The 1000 Brightest HIPASS Galaxies: H I Properties | journal=The Astronomical Journal | postscript=. | volume=128 | issue=1 | pages=16–46 | date=July 2004 | doi=10.1086/421744 | bibcode=2004AJ....128...16K | arxiv=astro-ph/0404436 | display-authors=1 }} 6. ^1 2 3 4 5 {{Citation | last1 = Bresolin | first1 = Fabio | last2 = Kennicutt | first2 = Robert C. | last3 = Ryan-Weber | first3 = Emma | display-authors = 1 | title = Gas Metallicities in the Extended Disks of NGC 1512 and NGC 3621. Chemical Signatures of Metal Mixing or Enriched Gas Accretion? | journal = The Astronomical Journal | volume = 750 | issue = 2 | page = 122 |date=May 2012 | doi = 10.1088/0004-637X/750/2/122 | bibcode = 2012ApJ...750..122B | arxiv = 1203.0956 | postscript= .}} 7. ^1 2 {{Citation | last1 = Barth | first1 = Aaron J. | last2 = Strigari | first2 = Louis E. | last3 = Bentz | first3 = Misty C. | last4 = Greene | first4 = Jenny E. | last5 = Ho | first5 = Luis C. | display-authors = 1 | title = Dynamical Constraints on the Masses of the Nuclear Star Cluster and Black Hole in the Late-Type Spiral Galaxy NGC 3621 | journal = The Astronomical Journal | volume = 690 | issue = 1 | pages = 1031–1044 |date=January 2009 | doi = 10.1088/0004-637X/690/1/1031 | bibcode = 2009ApJ...690.1031B | arxiv = 0809.1066 | postscript= .}} }} External links
3 : Unbarred spiral galaxies|Field galaxies|NGC objects |
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