NGC 5005, also known as Caldwell 29, is an inclined

spiral galaxy Spiral galaxies form a galaxy morphological classification, class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''

Canes Venatici Canes Venatici ( ) is one of the 88 constellations designated by the International Astronomical Union (IAU). It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for 'hunting dogs', and ...

. It was discovered by German-British astronomer

William Herschel Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover ...

on 1 May 1785. The galaxy has a relatively bright nucleus and a bright disk that contains multiple dust lanes. The galaxy's high surface brightness makes it an object that is visible to amateur astronomers using large amateur telescopes. Distance measurements for NGC 5005 vary from 13.7

megaparsecs The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (AU), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and ...

(45 million

light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

s) to 34.6 megaparsecs (113 million light-years), averaging about 20 megaparsecs (65 million light-years).

Supernova

One

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

has been observed in NGC 5005: SN 1996ai ( Type Ia, mag. 14.5) was discovered by Claudio Bottari on 16 June 1996.

Nucleus

NGC 5005 contains a

low ionization nuclear emission region A low-ionization nuclear emission-line region (LINER) is a type of galaxy, galactic galaxy nucleus, nucleus that is defined by its spectral line, spectral line emission. The spectra typically include line emission from ion, weakly ionized or neu ...

(LINER) nucleus. LINER nuclei contain weakly

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

ized gas. The power source for the LINER emission has been debated extensively, with some researchers suggesting that LINERs are powered by

active galactic nuclei 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 e ...

that contain

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical ...

s and other researchers suggesting that LINERs are powered by

star formation Star formation is the process by which dense regions within molecular clouds in interstellar space—sometimes referred to as "stellar nurseries" or "star-forming regions"—Jeans instability, collapse and form stars. As a branch of astronomy, sta ...

activity.

X-ray emission

X-ray observations of NGC 5005 have revealed that it contains a variable, point-like hard

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

source in its nucleus. These results imply that NGC 5005 contains a

. The strong, variable X-ray emission is characteristic of the emission expected from the hot, compressed gas in the environment outside a black hole in an

active galactic nucleus 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 e ...

Companion galaxy

NGC 5005 and the nearby spiral galaxy

NGC 5033 NGC 5033 is an inclined spiral galaxy located in the constellation Canes Venatici. Its velocity with respect to the cosmic microwave background is , which corresponds to a Hubble distance of . Additionally, 25 ''non-redshift'' measurements give ...

comprise a physical galaxy pair. The two galaxies weakly influence each other gravitationally, but they are not yet close enough to each other to be distorted by the

tidal forces The tidal force or tide-generating force is the difference in gravitational attraction between different points in a gravitational field, causing bodies to be pulled unevenly and as a result are being stretched towards the attraction. It is the d ...

of the gravitational interaction.

Notes

External links