Local Volume

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Local Volume
Known number of galaxies 500 [1]
Brightest member Milky Way
Semi-major axis 11 Mpc (35.9 million light years) [2]
Diameter 22 Mpc (71.8 million light years)
Redshift 0.00 (0 km/s)
Distance 0 Mpc (0 million light years)

The Local Volume is a collection of more than 500 galaxies located in an area of the observable universe near us, within a spherical region with a radius of 11 megaparsecs from Earth or up to a radial velocity of redshift of z < 0.002 (550 km/s). [3] [4] [5]

Contents

It was in this region of the universe where the Local Volume Legacy (LVL) project took place for the study of 258 galaxies through cycles of observations made by the Spitzer Space Telescope using the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPS). [6] [7] [8] [9]

Partial representation of the Local Volume (the scale at the top represents 5 million light-years). Nearest Groups of Galaxies atlasoftheuniverse.gif
Partial representation of the Local Volume (the scale at the top represents 5 million light-years).

This Local Volume study included all galaxies within a 3.5 megaparsec subvolume and a collection of spiral and irregular galaxies within 11 megaparsecs. The goals of the study were to collect data on the rate of star formation, stellar mass in old star populations, cosmic dust, and starlight interference. [10]

We can also define the Local Volume by the distance of 10 Mpc over which the Hubble Space Telescope can distinguish stellar populations in galaxies. This definition can be extended to 15 Mpc to cover a full range of galaxy environments, from voids to clusters and massive clusters. In the future, it should be possible to extend our definition of Local Volume to even greater distances.

Within the Local Volume is the Local Sheet, an area of flattened space containing about 60 galaxies that share the same velocity and is about 7 megaparsecs in radius and about 0.5 megaparsecs thick. The Local Group, of which the Milky Way and the Andromeda galaxy are part, is part of the Local Sheet and therefore, of the Local Volume. The Local Volume, in turn, is included in the Laniakea Supercluster.

Local Volume galaxies have a preferred movement called virgocentric flow, towards the Virgo cluster, caused by its overwhelming gravity. [11]

Among the member galaxies of the Local Volume, there are several large galaxies or particular galaxies such as Centaurus A, the Bode galaxy (M81), the Cigar galaxy (M82), the Circinus galaxy, the Southern Pinwheel galaxy (M83), the Pinwheel galaxy (M101), the Sombrero Galaxy (M104), NGC 1512, M51, M74, M66 and M96. [12]

Recently, following Hubble Space Telescope observations, two dwarf galaxies, Pisces A and Pisces B, have been identified as having migrated into the Local Volume from the neighboring Local Void. [13]

See also

Related Research Articles

Local Group Group of galaxies that includes the Milky Way

The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly 3 megaparsecs (10 million light-years; 9×1022 metres), and a total mass of the order of 2×1012 solar masses (4×1042 kg). It consists of two collections of galaxies in a "dumbbell" shape: the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about 800 kpc (3×10^6 ly; 2×1022 m) and are moving toward one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies.

M81 Group Galaxy group in Ursa Major and Camelopardalis

The M81 Group is a galaxy group in the constellations Ursa Major and Camelopardalis that includes the galaxies Messier 81 and Messier 82, as well as several other galaxies with high apparent brightnesses. The approximate center of the group is located at a distance of 3.6 Mpc, making it one of the nearest groups to the Local Group. The group is estimated to have a total mass of ×1012M. The M81 Group, the Local Group, and other nearby groups all lie within the Virgo Supercluster.

Supercluster Large group of smaller galaxy clusters or galaxy groups

A supercluster is a large group of smaller galaxy clusters or galaxy groups; they are among the largest known structures in the universe. The Milky Way is part of the Local Group galaxy group, which in turn is part of the Virgo Supercluster, which is part of the Laniakea Supercluster. The large size and low density of superclusters means that they, unlike clusters, expand with the Hubble expansion. The number of superclusters in the observable universe is estimated to be 10 million.

Virgo Supercluster Galactic supercluster containing the Virgo Cluster

The Virgo Supercluster or the Local Supercluster is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which in turn contains the Milky Way and Andromeda galaxies. At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs. The Virgo SC is one of about 10 million superclusters in the observable universe and is in the Pisces–Cetus Supercluster Complex, a galaxy filament.

Messier 81 Grand design spiral galaxy in the constellation Ursa Major

Messier 81 is a grand design spiral galaxy about 12 million light-years away, with a diameter of 90,000 light years, in the constellation Ursa Major. Due to its proximity to our galaxy, large size, and active galactic nucleus, Messier 81 has been studied extensively by professional astronomers. The galaxy's large size and relatively high brightness also makes it a popular target for amateur astronomers. In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.

Sombrero Galaxy Spiral galaxy in the constellation Virgo

The Sombrero Galaxy is a spiral galaxy in the constellation borders of Virgo and Corvus, being about 9.55 megaparsecs from our galaxy, within the local supercluster. It has a diameter of approximately 15 kiloparsecs, three-tenths the size of the Milky Way. It has a bright nucleus, an unusually large central bulge, and a prominent dust lane in its outer disk, which is viewed almost edge-on. The dark dust lane and the bulge give it the appearance of a sombrero hat. Astronomers initially thought the halo was small and light, indicative of a spiral galaxy; but the Spitzer Space Telescope found that the dust ring was larger and more massive than previously thought, indicative of a giant elliptical galaxy. The galaxy has an apparent magnitude of +8.0, making it easily visible with amateur telescopes, and is considered by some authors to be the galaxy with the highest absolute magnitude within a radius of 10 megaparsecs of the Milky Way. Its large bulge, central supermassive black hole, and dust lane all attract the attention of professional astronomers.

Robert Charles Kennicutt, Jr. FRS is an American astronomer. He is currently a professor at Texas A&M University. He is a former Plumian Professor of Astronomy at the Institute of Astronomy in the University of Cambridge. He was formerly Editor-in-Chief of the Astrophysical Journal (1999–2006) and became a co-editor of the Annual Review of Astronomy and Astrophysics as of 2021. His research interests include the structure and evolution of galaxies and star formation in galaxies.

Bubble Nebula (NGC 6822) Nebula in Barnards Galaxy in the constellation Sagittarius

The Bubble Nebula in Barnard's Galaxy has the official designation of Hubble 1925 I as it was the first object recorded in a paper by E. Hubble 1925. It includes areas of bright H II emission. It is located north-west of the larger Hubble 1925 III.

Pavo–Indus Supercluster Neighboring supercluster in the constellations Pavo,Indus and Telescopium

The Pavo-Indus Supercluster is a neighboring supercluster located about 60–70 Mpc (196–228 Mly) away in the constellations of Pavo, Indus, and Telescopium. The supercluster contains three main clusters, Abell 3656, Abell 3698, and Abell 3742.

Location of Earth Knowledge of the location of Earth

Knowledge of the location of Earth has been shaped by 400 years of telescopic observations, and has expanded radically since the start of the 20th century. Initially, Earth was believed to be the center of the Universe, which consisted only of those planets visible with the naked eye and an outlying sphere of fixed stars. After the acceptance of the heliocentric model in the 17th century, observations by William Herschel and others showed that the Sun lay within a vast, disc-shaped galaxy of stars. By the 20th century, observations of spiral nebulae revealed that the Milky Way galaxy was one of billions in an expanding universe, grouped into clusters and superclusters. By the end of the 20th century, the overall structure of the visible universe was becoming clearer, with superclusters forming into a vast web of filaments and voids. Superclusters, filaments and voids are the largest coherent structures in the Universe that we can observe. At still larger scales the Universe becomes homogeneous, meaning that all its parts have on average the same density, composition and structure.

Galaxy filament Largest structures in the universe, made of galaxies

In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of gravitationally bound galaxy superclusters. These massive, thread-like formations can reach 80 megaparsecs h−1 and form the boundaries between large voids.

The Pisces–Cetus Supercluster Complex is a galaxy filament. It includes the Laniakea Supercluster which contains the Virgo Supercluster lobe which in turn contains the Local Group, the galaxy cluster that includes the Milky Way. This filament is adjacent to the Perseus–Pegasus Filament.

NGC 59 Lenticular galaxy in the constellation Cetus

NGC 59 is a lenticular galaxy in the constellation Cetus. It is a probable member of the Sculptor Group. It is approximately 17 million light-years away.

Laniakea Supercluster Galaxy supercluster that is home to the Milky Way Galaxy and many more galaxies

The Laniakea Supercluster is the galaxy supercluster that is home to the Milky Way and approximately 100,000 other nearby galaxies. It was defined in September 2014, when a group of astronomers including R. Brent Tully of the University of Hawaiʻi, Hélène Courtois of the University of Lyon, Yehuda Hoffman of the Hebrew University of Jerusalem, and Daniel Pomarède of CEA Université Paris-Saclay published a new way of defining superclusters according to the relative velocities of galaxies. The new definition of the local supercluster subsumes the prior defined local supercluster, the Virgo Supercluster, as an appendage.

The Taurus Void is a vast, near-empty region of space situated between the Perseus-Pisces Supercluster and the Virgo Supercluster. The Taurus void is unique because of its relatively close proximity to Earth, and because it helps to define the edge of latter's home supercluster, the Virgo Supercluster. Despite its close proximity to Earth, the Taurus Void is not well-studied because it is partially obscured by the Milky Way when viewed from Earth. In contrast to its ambiguous boundary in the section of sky obscured by the Milky Way, the Taurus Void has a very well-defined boundary with the Perseus-Pisces supercluster.

NGC 5238 Irregular galaxy in constellation Canes Venatici

NGC 5238 is an irregular galaxy in the constellation Canes Venatici. Located at a comoving distance of 4.51 Mpc, it is 64.4 arcseconds in diameter. It has sometimes been classified as a blue compact dwarf galaxy. Although some authors have hypothesized it to be a member of the M101 Group of galaxies, it is currently believed to be an isolated galaxy.

Pisces A Void dwarf Galaxy in the constellation Pisces

Pisces A is a void dwarf galaxy. It is located in the Local Void, near Pisces B; and is in the Pisces constellation. It is 18.4 million light-years away from Earth. The galaxy was discovered with the WIYN Observatory. About 100 million years ago, the galaxy started moving out of the void and into the local filament zone and denser gaseous environment. This sparked off a doubling of the rate of star formation.

The Vela Supercluster (Vela SCl, VSCL) is a massive galactic supercluster about 265.5 megaparsecs (870 million light-years) away within the vicinity of the Zone of Avoidance, centered on the constellation Vela. It is one of the largest structures found in the universe, covering about 25 × 20 degrees of the sky. It consists of two walls: a broad main wall and a secondary merging wall. The combined dimensions of the walls are 115 km/s Mpc on the major dimensions and 90 km/s Mpc on the minor ones, which corresponds to about 385 million and 300 million light years, respectively. It is about 1,000 times the mass of the Milky Way galaxy, which corresponds to a mass of 1 × 1015 M. About 20 initial galaxy clusters have been identified spectroscopically.

KBC Void Large, comparatively empty region of space

The KBC Void is an immense, comparatively empty region of space, named after astronomers Ryan Keenan, Amy Barger, and Lennox Cowie, who studied it in 2013. The existence of a local underdensity has been the subject of many pieces of literature and research articles.

References

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  2. "Local Volume H i Survey (LVHIS) | Monthly Notices of the Royal Astronomical Society | Oxford Academic". academic.oup.com. Retrieved 2022-01-26.
  3. "Galaxy and Mass Assembly (GAMA): galaxies at the faint end of the Hα luminosity function | Monthly Notices of the Royal Astronomical Society | Oxford Academic". academic.oup.com. Retrieved 2022-02-14.
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  5. "Codex Cosmi". www.caelus.fi. Retrieved 2022-02-14.
  6. Lee, J. C.; Kennicutt, R. C.; Engelbracht, C. W.; Calzetti, D.; Dale, D. A.; Gordon, K. D.; Dalcanton, J. J.; Skillman, E.; Begum, A. (2008-10-01). "The Local Volume Legacy Survey". Formation and Evolution of Galaxy Disks. 396: 151. Bibcode:2008ASPC..396..151L . Retrieved 2022-01-25.
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  9. "Spitzer Local Volume Legacy (LVL) SEDs and physical properties | Monthly Notices of the Royal Astronomical Society | Oxford Academic". academic.oup.com. Retrieved 2022-01-25.
  10. Karachentsev, I. D.; Kaisina, E. I. (2019-05-21). "Dwarf Galaxies in the Local Volume". Astrophysical Bulletin. 74 (2): 111–127. arXiv: 1905.08477 . Bibcode:2019AstBu..74..111K. doi:10.1134/S1990341319020019. ISSN   1990-3413. S2CID   160010132 . Retrieved 2022-01-25.
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  12. "A Catalog of Neighboring Galaxies" . Retrieved 2022-02-10.
  13. "Hubble Uncovers a Galaxy Pair Coming in from the Wilderness". 2020-11-08. Archived from the original on 2020-11-08. Retrieved 2022-01-25.