One-color image of the disturbed galaxy Arp-Madore 135-650, also known as NGC 646. This was observed for one of the gap-filler programs. If I could make a color image, it might appear blueish up top where all the star formation is ongoing, and less blue at the bottom. This is what makes the galaxy interesting, according to a brief mention on Twitter by principle investigator Julianne Dalcanton: twitter.com/dalcantonJD/status/1038436462876741633
The puzzle is to figure out why is it all clumpy and star-formy on one side, but smooth and not so much on the other side.
I cleaned off a satellite trail and a few hundred cosmic rays.
Data from the following proposal is used to create this image:
Establishing HST's Low Redshift Archive of Interacting Systems
All channels: ACS/WFC F606W
North is NOT up. It is 43.07° counter-clockwise from up.
Tags: spiral galaxy interacting disturbed star formation HST Hubble 15446 PropID15446 NGC646
A picturesque spiral galaxy perhaps most notable for being the 6000th entry in the New General Catalog. Hubble has looked at this galaxy a few times for stellar and galactic surveying, but never specifically because there is anything about this galaxy that makes it interesting on its own. Beautiful, but typical. I will say that the small, bright spiral in the nucleus amuses me. If I were to turn it 180°, it would be a 6, which would be fitting for it since it is NGC 6000. However, I think that would look "upside-down" if there is such a thing for galaxies.
There is an asteroid trail somewhere in this picture.
The chip gap was filled with cloned data. The image has clarity, sharpness, and saturation adjustments.
Data from Proposal 15166 were used to create this image.
Continuing a Snapshot Survey of the Sites of Recent, Nearby Supernovae: Cycles 25 & 26
Red: WFC3/UVIS F814W
Green: Pseudo
Blue: WFC3/UVIS F555W
North is NOT up. It is 60.43° clockwise from up.
Tags: galaxy spiral NGC6000 Hubble HST near-infrared visible stars SN2010AS bulge bar PropID15166 15166
This image is intended to show the details around the central black hole of NGC 5643. Visible in blueish hues is a cone of light emanating from the bright nucleus. Though black holes are known for being so massive that not even light can escape them, they also power processes around them that create some of the brightest phenomena known to astronomers. This light is so intense that it is causing gas to glow many hundreds of light years away from the black hole. The disk of the galaxy is obscuring the rear facing cone of light, but I think I see a little bit of blue peeking out at the upper right.
Peter Maksym's narrowband data coming out of its proprietary period at the end of 2018 should allow for an even clearer, more stunning image to be created. Funny enough, most of the data comprising this image were taken a few months afterward, but Adam Riess's observations have no proprietary period for reasons that are not totally clear to me.
An image showing a much wider view of the galaxy is available here: flic.kr/p/FG6vwk
Data from the following proposals were used to compose this image:
The Hubble Constant to 1%: Physics beyond LambdaCDM
The Fueling of Active Nuclei: Why are Active Galaxies Active?
Red: WFC3/IR F160W
Green: WFC3/UVIS F814W
Blue: WFC3/UVIS F555W
North is NOT up. It is 31.91° counter-clockwise from up.
Tags: spiral galaxy barred Active Galactic Nucleus Hubble HST black hole visible near infrared 15145 8597 PropID8597 PropID15145
Home to an another active nucleus, NGC 5643 is a picturesque barred spiral galaxy with spiral arms intertwined in such a way to make them difficult to count. It is similar in size to our own Milky Way, and one might surmise that it looks somewhat similar to our home galaxy, if not for the active nucleus. Older, yellowish colored stars gather in the center and along the bar, while younger stars and regions of star formation populate the periphery, giving rise to the variation in colors for the image. Dark streaks of umber trace dust in the galaxy's complicated arms. Even though this image is mostly near-infrared, the colors look similar to a traditional visible light image.
Due to the relative brightness of the core, it was necessary to create a second image of the galaxy detailing the nuclear region. That is available here: flic.kr/p/25mnGPD
Data from the following proposals were used to compose this image:
The Hubble Constant to 1%: Physics beyond LambdaCDM
The Fueling of Active Nuclei: Why are Active Galaxies Active?
Note there was a data gap just south of the nucleus where no WFC3 data were available. Some older WF/PC2 data were used to fill that in.
Red: WFC3/IR F160W
Green: WFC3/UVIS F814W
Blue: WFC3/UVIS F555W
North is NOT up. It is 31.91° counter-clockwise from up.
Tags: spiral galaxy barred Active Galactic Nucleus Hubble HST black hole visible near infrared PropID15145 15145 PropID8597 8597
I'm still on a roll with the active galactic nuclei (AGN) and here is the latest, with thanks to Mitchell Revalski et al. for the list of interesting objects to investigate. I had the usual trouble with this one trying to balance the colors while making the illuminated filaments easy to discern. In many galaxies, the details near the nucleus are not so important to convey, and it is therefore ok if it's all a bright ball. Here, the image is quite dark to accommodate the details in the core.
We're quite used to seeing spiral galaxies with uniformly yellowish cores full of old stars, so when something blue or green is spotted, it seems a bit odd, and that's one of the ways astronomers can find these fascinating galaxies. Such nuances are picked out relatively easily by comparing spectroscopic results from many different galaxies. Spectroscopy is kind of like a fingerprint in light, and whatever spikes and dips in the graph appear tell a story about how far the light traveled, what elements are present, and what's happening to those elements.
Apparently there is not just one black hole at the center of this galaxy, but a pair that are eventually going to merge. Would you believe that spectroscopy can also tell us this? This is moving into the realm of things I don't understand well enough to explain, but here are a number of papers specifically on the case of this galaxy.
arxiv.org/find/all/1/all:+AND+NGC+3393/0/1/0/all/0/1
Data from the following proposal were used to create this image:
The Hosts of Megamaser Disk Galaxies
The representation of filters was a bit difficult, as I used some near-infrared data for around the core, but it didn't extend all the way to the edge, and I had to make up for it with the F814W data there. With that in mind, colors are as follows:
Red: WFC3/IR F160W + WFC3/IR F110W
Green: WFC3/UVIS F814W
Blue: WFC3/UVIS F438W + WFC3/UVIS F336W
North is NOT up. It is 38.67° counter-clockwise from up.
Tags: spiral galaxy AGN Active Galactic Nucleus black hole NGC3393 HST Hubble 12185 PropID12185