ScottH
December 8th, 2024, 11:12 PM
Designations: MCG -06-09-030, ESO 358-G63, PGC 013809, FCC 312
Nickname: The Subtle Knife
Constellation: Fornax
Type: Spiral Galaxy 14.4° from edge-on
RA 03:46:19
DEC -34:56:37
Magnitude: 11.8
Size: 4.7’ x 1.25’
Distance: 60 million light-years
Down south, in a region spanning from Fornax into Eridanus, is the second richest galaxy cluster within 100 million light-years. Its brightest members, shining at 10th-magnitude and better, were first discovered in 1826 by the Scottish observer James Dunlop, who was observing from Australia at the time. But it wasn’t until 1943 that it was declared a bonafide galaxy cluster [1].
Compared to the well-known Virgo Cluster, Fornax is about one magnitude smaller in total halo mass, meaning the density of the intracluster medium and the velocity dispersion of its galaxy population are lower. It’s dominated by an overdensity centered on the large elliptical galaxy NGC 1399, and has a lower density substructure surrounding the radio galaxy NGC 1316 (aka Fornax A) located to the southwest [2]. It’s a dynamically and structurally complex system, with the two main components likely in the process of merging and accompanied by the presence of other substructures and filaments.
5601
Iodice et al (2019) (https://ui.adsabs.harvard.edu/abs/2019A%26A...623A...1I/abstract) VST mosaic in the g band of the Fornax cluster inside the virial radius. The image size is about 9 square degrees. Black contours are the X-Ray emission from ROSAT (Paolillo et al. 2002). The X-ray contours are spaced by a factor of 1.3. All ETGs studied in the present work are labelled on the image. Galaxies marked with blue symbols have g - i < 0.8 mag and g - r < 0.4 mag. North is up, East is on the left. MCG -06-09-030 lies up along the upper left edge.
In his 1989 paper titled “A Catalog of Galaxies in the Central 3.5° of the Fornax Cluster”, astronomer Henry Ferguson presented a catalog of 340 likely cluster members [3]. And of all the members he cataloged – which included over three dozen from the NGC/IC – the brightest one not in the NGC/IC is FCC 312. What’s surprising is that not only is it brighter than over a dozen other NGC/IC member galaxies, but it lies less than 2° from dominating NGC 1399.
That galaxy first appeared in the fifth installment of Vorontsov-Vel’yaminov and Arkhipova’s Morphological Catalogue of Galaxies, which was published in 1974. Given the designation MCG -06-09-030, its type was classed as Sc/Irr. At a distance of around 60 million light-years, it’s a spiral galaxy being viewed 14.4° from edge-on [4].
5600
Image crop from Legacy Survey DR9
Have you ever seen an image of it? I bet not. Unlike a lot of the brightest members of the Fornax Cluster, it lies northeast of NGC 1399 and pretty much always just outside the field. Take for example Gary Imm’s image (https://www.astrobin.com/rs10js/). He did a great job capturing a bunch of galaxies, but MCG -06-09-030 is outside the field by just 0.5° to the left!
I’d wager that the galaxy is visible in telescopes with single-digit aperture from either earthly hemisphere. I meant to observe it with my 10-inch last week, but was always too busy making more pressing observations. However, I did manage to find the time to make one quick observation with my 16-inch. I found that I could just glimpse the galaxy as a sliver of light at only 68x.
Now, I'm not a big fan of forcing nicknames on objects. Heck, I'm not a big fan of nicknames in the first place! But, very rarely, I can sometimes be struck by an objects appearance and a nickname will come to me easily. For this galaxy, I've been calling it the "Subtle Knife" galaxy for several years now and think it makes a lot of sense in the context that it's been there this whole time but just not quite catching our eyes. Also, I'm a huge fan of Philip Pullman's Dark Materials trilogy...
As always, please "give it a go and let us know"!
References
[1] Shapley 1943 (https://ui.adsabs.harvard.edu/abs/1943galx.book...50S/abstract)
[2] Maddox et al 2019 (https://ui.adsabs.harvard.edu/abs/2019MNRAS.490.1666M/abstract)
[3] Ferguson 1989 (https://ui.adsabs.harvard.edu/abs/1989AJ.....98..367F/abstract)
[4] Hodges-Kluck et al 2016 (https://ui.adsabs.harvard.edu/abs/2016ApJ...833...58H/abstract)
Nickname: The Subtle Knife
Constellation: Fornax
Type: Spiral Galaxy 14.4° from edge-on
RA 03:46:19
DEC -34:56:37
Magnitude: 11.8
Size: 4.7’ x 1.25’
Distance: 60 million light-years
Down south, in a region spanning from Fornax into Eridanus, is the second richest galaxy cluster within 100 million light-years. Its brightest members, shining at 10th-magnitude and better, were first discovered in 1826 by the Scottish observer James Dunlop, who was observing from Australia at the time. But it wasn’t until 1943 that it was declared a bonafide galaxy cluster [1].
Compared to the well-known Virgo Cluster, Fornax is about one magnitude smaller in total halo mass, meaning the density of the intracluster medium and the velocity dispersion of its galaxy population are lower. It’s dominated by an overdensity centered on the large elliptical galaxy NGC 1399, and has a lower density substructure surrounding the radio galaxy NGC 1316 (aka Fornax A) located to the southwest [2]. It’s a dynamically and structurally complex system, with the two main components likely in the process of merging and accompanied by the presence of other substructures and filaments.
5601
Iodice et al (2019) (https://ui.adsabs.harvard.edu/abs/2019A%26A...623A...1I/abstract) VST mosaic in the g band of the Fornax cluster inside the virial radius. The image size is about 9 square degrees. Black contours are the X-Ray emission from ROSAT (Paolillo et al. 2002). The X-ray contours are spaced by a factor of 1.3. All ETGs studied in the present work are labelled on the image. Galaxies marked with blue symbols have g - i < 0.8 mag and g - r < 0.4 mag. North is up, East is on the left. MCG -06-09-030 lies up along the upper left edge.
In his 1989 paper titled “A Catalog of Galaxies in the Central 3.5° of the Fornax Cluster”, astronomer Henry Ferguson presented a catalog of 340 likely cluster members [3]. And of all the members he cataloged – which included over three dozen from the NGC/IC – the brightest one not in the NGC/IC is FCC 312. What’s surprising is that not only is it brighter than over a dozen other NGC/IC member galaxies, but it lies less than 2° from dominating NGC 1399.
That galaxy first appeared in the fifth installment of Vorontsov-Vel’yaminov and Arkhipova’s Morphological Catalogue of Galaxies, which was published in 1974. Given the designation MCG -06-09-030, its type was classed as Sc/Irr. At a distance of around 60 million light-years, it’s a spiral galaxy being viewed 14.4° from edge-on [4].
5600
Image crop from Legacy Survey DR9
Have you ever seen an image of it? I bet not. Unlike a lot of the brightest members of the Fornax Cluster, it lies northeast of NGC 1399 and pretty much always just outside the field. Take for example Gary Imm’s image (https://www.astrobin.com/rs10js/). He did a great job capturing a bunch of galaxies, but MCG -06-09-030 is outside the field by just 0.5° to the left!
I’d wager that the galaxy is visible in telescopes with single-digit aperture from either earthly hemisphere. I meant to observe it with my 10-inch last week, but was always too busy making more pressing observations. However, I did manage to find the time to make one quick observation with my 16-inch. I found that I could just glimpse the galaxy as a sliver of light at only 68x.
Now, I'm not a big fan of forcing nicknames on objects. Heck, I'm not a big fan of nicknames in the first place! But, very rarely, I can sometimes be struck by an objects appearance and a nickname will come to me easily. For this galaxy, I've been calling it the "Subtle Knife" galaxy for several years now and think it makes a lot of sense in the context that it's been there this whole time but just not quite catching our eyes. Also, I'm a huge fan of Philip Pullman's Dark Materials trilogy...
As always, please "give it a go and let us know"!
References
[1] Shapley 1943 (https://ui.adsabs.harvard.edu/abs/1943galx.book...50S/abstract)
[2] Maddox et al 2019 (https://ui.adsabs.harvard.edu/abs/2019MNRAS.490.1666M/abstract)
[3] Ferguson 1989 (https://ui.adsabs.harvard.edu/abs/1989AJ.....98..367F/abstract)
[4] Hodges-Kluck et al 2016 (https://ui.adsabs.harvard.edu/abs/2016ApJ...833...58H/abstract)