The Markarian galaxies are a class of galaxies that have nuclei with excessive amounts of

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation ...

emissions compared with other galaxies. Benjamin Markarian drew attention to these types of galaxies starting in 1963. The nuclei of the galaxies had a blue colour, associated to stars in the classes from O to A. This blue core did not match the rest of the galaxy. The

spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors ...

in detail tends to show a continuum that Markarian concluded was produced non- thermally. Most of these have

emission line A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identi ...

s and are characterized by highly energetic activity. Markarian Catalogue entries are of the form "Markarian ####", and can frequently use the abbreviations Mrk, Mkr, Mkn; and rarely Ma, Mk, Mark.

History

In 1964 Markarian decided to search for this kind of galaxy. The First Byurakan Survey commenced in 1965 using the

Schmidt telescope Schmidt may refer to: * Schmidt (surname), including list of people with the surname * Schmidt (singer) (born 1990), German pop and jazz singer * Schmidt (lunar crater), a small lunar impact crater * Schmidt (Martian crater), a crater on Mars * ...

at the Byurakan Astrophysical Observatory in Armenian SSR. The telescope used a 132 cm mirror and 102 cm correcting plate. When this started it was the largest telescope to have a full aperture objective prism. The purpose of the survey was to find galaxies with an ultraviolet excess. The optics used were corrected for blue violet. Prisms in this had a low dispersion of 180 nm/mm in order not to spread out the galactic core spectrum too much and confuse it with other objects. This permitted classification of galaxies with magnitudes down to 17.5. Seventy galaxies with UV-continuum appeared on lists, and the term "Markarian galaxies" came into use. Two more lists brought the number of galaxies up to 302 in 1969. The FBS continued observations till 1978 with a full spectra survey at high galactic latitudes. 1980 saw the completion of plate analysis and picking the objects that would be included. Twelve more papers with objects from the First Byurakan Survey brought the list up to 1500 galaxies. A list titled "First Byurakan Survey" circulated in 1986, including the original 1500 galaxies and 32 extras numbered from 9001 to 9032. In 1989 an extended list numbering up to 1515 was published. In 2005, the " Second Byurakan Survey" (SBS, SBSSS, BSS, MrkII, Markarian II) was carried out, extending the MrkI survey to fainter objects, making a catalogue of 3563 objects of 1863 galaxies (SBSG) and 1700 stars (SBSS); 761 of the galaxies are AGN (155 Seyferts, 596 quasars, 10 blazars).

Characteristics

The catalogues of galaxies included a name, coordinates, spectral type, visible size and morphological type of galaxy. A custom designator for the galaxy core of "s" for star-like or "d" for diffuse was used, with hybrids of "ds" or "sd". A digit 1,2 or 3 indicated strong, moderate or weak UV emission. A letter "e" was appended if emission lines were apparent. Eleven galaxies had a blue star in the foreground creating the ultraviolet excess, so these galaxies do not really fall into the class. Another problem is duplicate entries where Mrk 107 is Mrk 20, Mrk 1318 is Mrk 49, and Mrk 890 is Mrk 503. The various objects in this catalogue include

Seyfert galaxies Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra ...

starburst galaxies A starburst galaxy is one undergoing an exceptionally high rate of star formation, as compared to the long-term average rate of star formation in the galaxy or the star formation rate observed in most other galaxies. For example, the star formatio ...

H II region An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds ...

active galactic nuclei An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not prod ...

, BL Lac objects and quasars. Some objects are actually giant glowing regions of ionized hydrogen in a galaxy including Mrk 59, 71, 86b, 94, 256b, 404, 489b, 1039, 1236, 1315, and 1379a. Other galaxies have black holes shooting hot gas in energetic jets. Many are variable, showing the brightness comes from a small region.

Publications listing the Markarian galaxies

Gallery

File:Hubble Interacting Galaxy NGC 3690 (2008-04-24).jpg, 171 File:NGC 4319 I HST2002.jpg, 205 File:Markarian 209.png, 209 File:Hubble Interacting Galaxy UGC 8058 (2008-04-24).jpg, 231 File:Hubble Interacting Galaxy NGC 5256 (2008-04-24).jpg, 266 File:Hubble Interacting Galaxy Mrk 273 (2008-04-24).jpg,

273 __NOTOC__ Year 273 ( CCLXXIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Tacitus and Placidianus (or, less frequently, year ...

File:Hubble Interacting Galaxy UGC 12812 (2008-04-24).jpg, 331 (top center) File:Mark421-U3WS2701M.jpg,

421 __NOTOC__ Year 421 ( CDXXI) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Agricola and Eustathius (or, less frequently, year 117 ...

File:MRK 0501 2MASS.jpg, 501 File:Markarian 509 (HST).tiff, 509 File:Hubble Interacting Galaxy NGC 7674 (2008-04-24).jpg, 533 File:Markarian 817 (captured by the Hubble Space Telescope).jpg,

817 __NOTOC__ Year 817 ( DCCCXVII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. Events By place Europe * Summer – Emperor Louis I issues an ''Ordinatio Imperii'', an imperial de ...

File:Hubble Interacting Galaxy VV 705 (2008-04-24).jpg, 848

References

External links