Latest Work

Hello, I am trying something new with my website. I mostly tend to my Flickr gallery at this point, so to reduce the upkeep and redundancy, I am using the Flickr API to pull my latest images straight from my gallery over there. Clicking on any image will simply take you to its page within my Flickr gallery (external link).

A categorical listing of work, separated into albums, is located here (external link).


Saturn in Methane Bands

Saturn in Methane Bands

Well, here’s a thing that was unexpectedly well-received over at my Twitter account. Originally I posted it as an amusing joke, but people loved it, so I finished processing it by getting rid of all the cosmic rays and trying to align the disturbances in some of the clouds near the north pole.

Why are the rings neon green, you ask? This is just how the colors end up looking when I try to white balance the cloud tops of Saturn in a given set of narrowband filters specifically designed to single out certain aspects of methane. In all of these filters, the rings are very bright; in fact the rings are so bright that they are lightly saturated (filled to completely white) in some places. However, Saturn’s clouds were very dark in the middle filter, which goes in the green channel, so when I tried to brighten the clouds to match with the red and the blue channels, the rings changed from their normally bright, whiteish color to a fluorescent green.

Bright moons visible in the image include Mimas at the lower left, Enceladus at the upper right, and Tethys at the middle right. There are also two faint moons just barely visible, both very close to the rings: Janus near the top of the rings, and Epimetheus centered at the bottom of the rings. I am not 100% sure that they are them, but given their positions and relative brightness to one another, this is my best guess.

These observations were originally taken on 2015 June 29 to study the storms, which were spotted by tireless amateur astronomers, near the northern pole. You may recall that Cassini was still operating at that time. However, the probe was not positioned optimally to capture the disturbances immediately, and it was worried that they would be largely missed. Hubble’s Director’s Discretionary budget was utilized to take the imagery relatively quickly. Presumably this means someone else’s observations were partially cancelled or pushed around since Hubble’s schedule is packed tightly, but this is how the cookie crumbles.

See:
A New Disturbance in Saturn’s North Sub-Polar Region

This image is scaled by 200% of its original resolution and then an unsharp mask was applied for sharpening.

Red: WFC3/UVIS FQ937N
Green: WFC3/UVIS FQ889N
Blue: WFC3/UVIS FQ727N

Hubble's Lagoon in Visible & Near-Infrared

Hubble's Lagoon in Visible & Near-Infrared

Another version of the anniversary dataset, this time with visible and near-infrared imagery combined into a single image. The pinks and cyans in the visible light version give way for near-infrared wavelengths by shifting into greens and deep blues. Now the near-infrared wavelengths comprise all the reds and oranges of the image. The gas and dust fade like ghosts, becoming nearly transparent, revealing many hundreds of stars once hidden from view.

One of my favorite things to do is to combine unusual or complicated datasets together.

ps - The original news release for the near-infrared only image is here, just in case you missed it. hubblesite.org/image/4151/news_release/2018-21

Data from the following proposal comprises this image:
ptical and infrared imaging of the Lagoon Nebula (M8)

There is also a WOW page providing direct access to data:
STScI Outreach Imaging of M8 (Lagoon Nebula) - April 2018

Red: WFC3/IR F160W
Orange: WFC3/IR F125W
Yellow-Green: WFC3/UVIS F658N
Green-Blue: WFC3/UVIS F656N
Cyan: WFC3/UVIS F547M
Blue: WFC3/UVIS F502N

North is NOT up. It is 133.99° clockwise from up.

Hubble's Lagoon

Hubble's Lagoon

Having fun with the anniversary data. The original observations were mostly narrowband, but I thought it would be fun to hack it a bit and give it a wideband look. Takes the focus away from the color patterns to allow one’s mind to appreciate the weight and shape of the structures more easily.

ps - The original news release image is here, just in case you missed it. hubblesite.org/image/4150/news_release/2018-21

Data from the following proposal comprises this image:
ptical and infrared imaging of the Lagoon Nebula (M8)

There is also a WOW page providing direct access to data:
STScI Outreach Imaging of M8 (Lagoon Nebula) - April 2018

Red: WFC3/UVIS F658N
Orange: WFC3/UVIS F656N
White: WFC3/UVIS F547M
Cyan: WFC3/UVIS F502N

North is NOT up. It is 133.99° clockwise from up.

Parallel Lagoon

Parallel Lagoon

Hubble’s recent 28th anniversary observations also included some parallel observations which were not part of the photo release. I’m totally here for that.

In this image, reddish, orange light represents mostly gaseous emission of energized hydrogen atoms, and muted, blueish gray areas are largely reflected starlight. This combination of light results in an image quality I am very fond of, but I must confess it took me a very long time to understand it beyond oooh, pretty. Once one understands that parts of the clouds are emitting light, while other parts are simply reflecting light, the shapes and coloration begin to make more sense. They are not very different in some ways from water clouds seen on Earth, but our water clouds are most frequently seen reflecting the Sun’s light, and not ever emitting their own light.

Interestingly, there are only two filters available to work with for the parallel observations. I wrongly guessed that the same filters used in the primary observations would end up being used in parallel. I don’t know why.

The proposal for these data is here:
Optical and infrared imaging of the Lagoon Nebula (M8)

Orange: ACS/WFC F658N
Cyan: ACS/WFC F550M

North is merely 1.05° counter-clockwise from up.

Circinus Galaxy

Circinus Galaxy

The Circinus Galaxy is an active spiral galaxy that lies near the plane of our Milky Way so that it is rather heavily obscured by intervening stars and whatever other gas and dust lies along our line-of-sight to it. The brightly glowing filaments are yellowish this time because I had two (!) sets of narrowband filters to work with instead of just one or none. Previously, my other images showed them as blue. In reality, I think they are likely a slight greenish color, but the coloration of such things as they might appear to our eyes is unimportant and an unrealistic expectation to have, as fun as it may be to consider.

What I was pleased to see here is the stark contrast in features between the H-alpha and [O III] emission features. The H-alpha features, presented here in red, which are commonly associated with star formation, are present in both star-forming areas and the light cones of the active nucleus. The [O III] features, presented in green, are present almost exclusively in the light cones. This intersection results in a yellow color, clearly illustrating the difference between light-emitting nebulas.

This was a difficult dataset to work with not only because of that, but because there were not very observations available. What images were there are also not rectangular or square in shape, but rather are the stairstep shape of the old WFPC2 camera. There were a few gaps and especially problematic were the yellowish filaments, because they were abruptly cut off.

Regarding the filaments: I was debating exactly how to show the entire nucleus without having the awkward cutoff, and finally arrived at a conclusion that is as far away from fictional as I could get it. Because the wideband data also overlaps with the narrowband data, I was able to recover the last of the details that were cut off and accurately portray the structure as it should appear in a whole image. I confirmed this later by comparing it to some ESO data. The image halfway down this page shows them in whole in blue: www.atnf.csiro.au/people/bkoribal/circinus/circinus.html


Some areas of the image contain cloned data because there were coverage gaps. I have uploaded am image with no cloned data to illustrate those areas: flic.kr/p/24fsf1X

Data from the following proposals were used to create this image:
The Far-Field Hubble Constant
The Early Evolution of Local Group Dwarf Irregular Galaxies
The Origin of Gaseous Outflows in Active Galaxies

Gray: WFPC2 F606W, WFPC2 F814W
Red overlay: WFPC2 F656N
Green overlay: WFPC2 F502N

North is up.

Active Nucleus of NGC 5643

Active Nucleus of NGC 5643

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.

NGC 5643

NGC 5643

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.

Active Nucleus of NGC 3227

Active Nucleus of NGC 3227

Super close-up view of the nucleus of NGC 3227. This time, there are a good number of filters to choose from, so color balancing was simple, but on the other hand, the field of view is quite narrow due to the use of the HRC. Hubble’s Advanced Camera for Surveys High Resolution Channel (HRC) once provided some of the most detailed imagery possible before it gave out. To give you an idea of how detailed, if it could be used to look at Neptune’s moon Triton right now, Triton would take up a little under 5x5 pixels on the detector. Good stuff.

NGC 3227 is a fun galaxy to look at. It’s interacting with another galaxy, NGC 3226, and the two of them are sloshing about past one another, leaving gas and stars streaming about them in multiple directions. Just from looking at them, one can almost imagine the two orbiting one another, reorganizing their contents in the process before eventually merging into one. Please have a look at them here, as they are a very good example of a pair of interacting galaxies: apod.nasa.gov/apod/ap131009.html

When I look at them, I ask myself, which one was bigger? Which was more dense? Could a bigger, but less dense galaxy be totally disrupted by a smaller, but more dense galaxy? Sure it could. Mass will always win out over size, as far as I know. But galaxies are not uniformly dense, and there is an extra component of dark matter to consider. The elliptical would seem to be the smaller one this time, but it could also be that it is a bit more distant than the spiral. They seem almost evenly matched to me.

Now that we have some context, we can understand a little better why even the nucleus of this spiral looks kind of disrupted. Star formation is ongoing as indicated by the reddish clouds of glowing hydrogen, and relatively bluer colored bright stars. The galaxy’s central supermassive black hole is also actively accreting, making it extremely bright. The glowing blue spotlights are not readily apparent this time. I have a few guesses why, but I also have a feeling that the situation is not so easy to ascertain. You know, I try to read some papers, and I don’t mind reading one or two, but the act of finding the right paper to read really gets me down.

Speaking of downers, Professor Stephen Hawking’s death was announced as I was writing this. Rest in peace…

Data from the following proposals were used to create this image:
The Black Hole Mass - Bulge Luminosity Relationship for the Nearest Reverberation-Mapped AGNs
Host Galaxies of Reverberation-Mapped AGNs
Massive Black Holes in Early Type Galaxies

Red: ACS/WFC F658N
Green: WFC3/UVIS F547M
Blue: ACS/HRC F550M + ACS/HRC F330W

North is NOT up. It is 45.00° counter-clockwise from up.

Active Nucleus of NGC 3393

Active Nucleus of NGC 3393

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.

Lagoon Window

Lagoon Window

Is there any more grand a canvas than space itself? Any more exquisite a pigment than softly glowing gas? Any finer brush than the subtle push and pull of starlight and gravity?

Gas and dust in the Lagoon Nebula. This is slightly off center from the brightest part of the nebula. You can see the edge of the brightest part at the top left of the image. The blue light emanating from the top is an artifact caused by a star just slightly off the edge of the detector. If it was a little further away, the flare would go away and only the usual diffraction spike would remain. It’s difficult to remove, but also kind of artistic, so it’s ok.

You may have seen a version of this image first at ESA’s website, here:
www.spacetelescope.org/images/heic1015a/

I put off doing this image for a long time because they’d already done it. The other night I decided to do it anyway, because I felt so sick, and needed something to look at between laying in bed. Rather than cutting the image in half, I filled the chip gap with cloned data. The chip gap is a 50 pixel wide gap running up and down the image where no real data exists. If you have followed me for long, you may remember it giving me grief many times in the past.

Anyway, this observation was taken in a search for proplyds, which is a shortened way of saying protoplanetary disks, which is a shortened way of saying dark, dusty disks of material in which the earliest stages of planetary formation are likely occurring around a star. After giving the whole image a rather thorough look, I’m not sure they found any proplyds here. Maybe I missed them, though.

The data comprising this image were observed as part of the following proposal:
A tailored survey of proplyds with the ACS

Red: ACS/WFC F660N
Green: ACS/WFC F558N
Blue: ACS/WFC F550M

North is NOT up. It is 150.00° clockwise from up.

There are more pictures at my Flickr Gallery (external link)