A wider field of view of the Markarian's Chain that I took earlier on, with quite a few extra goodies!!! I think galaxy shots look much better in B&W than in colour, especially widefield pics, as it invokes the old days of glass plates and "dodgy" film emulsions, although these are at a much higher resolution than most of them. Funny thing is the latest film emulsions you can get, especially in large format (say, 4x5) will blow any digital pic away as far as resolution goes. Even medium format film has a higher resolution than most digital cameras. However, it's the hassle of developing and scanning the film, plus the reciprocity failure and such which come to play when using film that stops most from using it. Mind you, I'll be giving it a go at some stage. Just to see what I can get!!! 🙂

Anyway, apart from all the galaxies in Markarians Chain, of which you all will be familiar with (at least those with astro-sense) , you have M87 (lower right of the chain), the main galaxy of the Virgo Cluster, a cD galaxy (cluster dominant) that is some 250Kly across and weighs in at around 10 trillion solar masses, or about 5 times our Galaxy's mass. In the core of the galaxy is a supermassive black hole that weighs in at around 6.5 billion solar masses and would encompass most of the Solar System should it replace the Sun. It's the little fella that took that piccie of just awhile back and at this scale you can't even see it 🙂 Also not visible at this resolution is M87's jet of material that's being erupted from the central black hole, the mechanism for which is a little too complicated to explain here, but involves the accretion disk and material inflow, the spin of the hole and a very large/powerful magnetic field surrounding the hole.

Moving away from M87, towards the far left corner, we come to M88 (NGC4501), a SA(rs)b class spiral galaxy which is also a member of the Virgo Group, lying at about the same distance as most of the rest of the galaxies in the group, around 50-60Mly. At that distance, its size of 6.9 arcminutes indicates it subtends 100356ly. It contains an estimated 400 billion stars, or about the same number of stars as our Galaxy does (from what we think we know of our Galaxy), but unlike our Galaxy doesn't have a central bar of stars. Its supermassive black hole is larger, at 80 million solar masses and the galaxy is classed as a Seyfert Type 2. It's believed the galaxy is on a highly elliptical orbit about the centre of the cluster, where M87 resides, and will approach the core of the cluster in about 200 million years. Presently, it's between 300-480Kly away from the core. Due to the motion through the cluster's ICM (Intracluster Medium...the hot gas between the galaxies in the cluster), ram pressure stripping of M88's gas in its outer regions is occurring. This can be seen at wavelengths other than visible light as a trail of gas behind the galaxy and is most noticeable at its western edge. From the Earth, the galaxy is tipped at 64 degrees to our line of sight, so we see it in a largely side on aspect.

Next galaxy in our little tour is NGC4429, which lies on the right hand side of the pic, about 75% of the way towards the top. At around 55.42Mly away, it's a shade further away than M88 but still very much a member of the Virgo Cluster. It's also tilted somewhat more so than M88, at 75 degrees to our line of sight. At 5.6 arcminutes in apparent size, this means it subtends a true diameter of 90277.6ly. Its Hubble Classification is SA0^+(r). The core of the galaxy exhibits a small dust disk as well as a cold circumnuclear disk of gas, which is indicative of a merger at some time in the past. However, the fact that the galaxy shows no outward signs of having merged with any other galaxy, this merger must have happened quite some time in the past. The central regions have a ring like structure to them and resemble the centre of the galaxy NGC7020 in that the nucleus appears to take on a hexagonal shape. Like M88, the galaxy is undergoing gas/mass loss due to ram pressure stripping. Oddly, the central regions of NGC4429 have an over abundance of magnesium, which is probably due to several different mechanism, one of which could be a high number of M class giants existing with in the core regions. Magnesium is outgassed by these stars during their planetary nebula phase in the sloughed off gases that once were their outer layers.

Next is NGC4371, which is at the 10 O'clock position w.r.t. NGC4429, towards the top of the pic. At a distance of 16.4Mpc (53.5Mly) the galaxy's apparent size of 3.88 arcminutes gives a true size of 60382.5ly. It's a lenticular galaxy, with a classification of S0-Aa, but in high resolution pics appears to have a bar like structure running across its short axis. Apart from the bar like structure, it's pretty much your average lenticular galaxy, though like its brethren, it's most likely undergoing ram pressure stripping of its gas.

We then go all the way down Markarian's Chain and then move to its upper left (slightly) till we come to NGC4459. It's located around 52.5Mly (16.1Mpc) from our Galaxy and its apparent size of 3.5 arcminutes at that distance gives a true size of 58032.1ly. Its Hubble Classification, like that of NGC4429, is SA0^+(r), meaning it's a lenticular galaxy. Also like 4429, it has an inner dust disk and a ring like structure in the nucleus. There is also evidence of ongoing star formation in this inner disk region, as evident in the fact that 4459 is a LINER galaxy. LINER stands for low ionisation nuclear emission region, which is a region of emission typified by spectral lines of weakly ionised or neutral gases such as O/O+, N+ and S+. It's usually associated with moderate to high star formation within the nucleus and where dying stars irradiate the gases surrounding themselves. The central supermassive black hole weighs in at around 70 million solar masses and is estimated to be around 2.87AU in diameter.

Halfway along a diagonal between NGC4429 and M87 lies a thin sliver of light, which is NGC4452. It's so thin, that its Hubble Classification is hard to determine, but it appears to be a spiral galaxy in nature. It is essentially edge on to us from our perspective. At its distance of around 60Mly (18.4Mpc), its apparent size of 2.7 arcminutes gives a true size of 47123.85ly. It appears to have a low dust content and maybe a lenticular galaxy, but it's hard to tell. Galaxies that appear this thin are rare as the Earth must lie within the extrapolated plane of the galaxy's disk, but as a whole galaxies this thin are very common, morphologically speaking. Our own Galaxy seen edge on would look fairly similar.

Finally, we come to NGC4440, a face on barred spiral galaxy lying 55Mly (16.87Mpc) away. Its classification is SB(rs)a, meaning a barred spiral galaxy with fairly openly wound arms and a just a hint of a circumnuclear ring structure surrounding a prominent nucleus. A very pretty looking galaxy, it appears face on to us, so we can see all of its structure quite clearly. The spiral arms emerge from the ends of the bar and wind over 180 degrees around the galaxy, giving the impression of a fairly tightly wound "S" shape. Its apparent size of 1.9 arcminutes at its distance gives a true size of 30397.8ly. Its recessional velocity is around 724km/s. In the pic, it lies at the 4 O'clock position w.r.t. M86 and almost at the 12 O'clock position directly above M87, at a point around halfway between the two.

As for the other galaxies present in the pic, there are far too many to talk about, most of them have IC catalogue numbers and would be easy to look up, should you feel like doing so.

Pic was taken with t20 (iTelescope, NMSO), 9x3min subs.