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Observing Time for Galaxy Zoo

It’s Christmas come early at Galaxy Zoo, with a healthy dose of everything that an astronomer would want under the tree – observing time.

We get to use this!

The Gemini South dome in suitably picturesque setting.

We didn’t get everything we asked the telescope allocation committees for, but we did get plenty to keep us busy well into the New Year. 2013 will see the following telescopes turned to Galaxy Zoo targets :

Gemini South: This 8m telescope in Chile (pictured above) will be observing bulgeless galaxies thanks to Brooke Simmons and her friends at Yale (especially Ezequiel Treister, now at Concepción in Chile). This is a program to look at the galaxies that were included in our first bulgeless paper, using deep, high-resolution spectroscopy to examine their stellar populations. For some objects where the AGN signal comes to us unobscured by dust and gas (but buried in a bright galaxy that made it hard to see in the SDSS spectra), we hope to also determine black hole masses with these deeper, finer spectra.

WIYN at Kitt Peak: This 3.5m telescope has recently been outfitted with a brand new imaging camera. As long as it keeps working the way it has been in tests, we can use it for 6 nights to examine whether our sample of bulgeless galaxies ever had minor mergers. Bulgeless galaxies are important because they’re supposed to be guaranteed merger-free so deep imaging of this kind helps us to confirm that that’s true by looking for any remnants of ripped-apart galaxies.

Bolshoi Teleskop Alt-azimutalnyi: This 6m telescope is important in astronomical history – it was once the largest in the world. It will be observing the Voorwerpjes as part of our increasing desire to understand these enigmatic objects – more on which is coming over the Christmas period, with any luck.

Shane Telescope at Lick: We’ve been awarded a second run on this telescope to look for ionized gas in the companion galaxies to those with active galactic nuclei – a sort of large scale Voorwerpje hunt.

There will be much more about all of these as the data starts to arrive, but we wanted to make sure that you know there were presents under the tree. We’re looking forward to unwrapping them immensely!

*Note: this post has been updated to more accurately reflect reality.

600 Most-Galaxified Words

When we launched the new Galaxy Zoo in September we also launched our ‘galaxify‘ tool, which allows you to write in an alphabet of Galaxy Zoo galaxies. Since that time you have created 320,000 messages, all written in galaxies! 18,468 contained the word ‘love’ and only 218 contain ‘hate’. 302 contained ‘marry me’ (5,853 contain swear words). Here’s the top 600 words so far, in one giant green word ball:

600words

Go write your own message at http://writing.galaxyzoo.org and don’t forget to check out the Zooniverse Advent Calendar for more fun items like this one in December.

Hangout with Galaxy Zoo: Science Chat Later Today

Later on today we’ll be holding a Google+ Hangout with a bunch of the Galaxy Zoo science team. We’ll be broadcasting this live at 3:30pm GMT (9:30am CST, 10:30am EST) and you’ll be able to see the video feed right here on the blog.

If you have any questions about the science behind Galaxy Zoo, short term loans UK and how to get them, or anything you’ve always wanted to ask the science team behind the project, please post them here as comments or contact us on Twitter @galaxyzoo.

We look forward to chatting later on and answering your questions.

We Need Your Help: Our New Astronomy Survey

This post is part of a series about the new Galaxy Zoo site. It is also part of Citizen Science September at the Zooniverse.

We are happy to announce that along with the new Galaxy Zoo release, we are also launching a new version of our Zooniverse astronomy survey. The new surveys were updated based on the many suggestions and responses we received from previous participants.

We are asking for your help so that we can develop a better understanding of the Galaxy Zoo participant base’s ideas in astronomy. The results from the new surveys will also be used to inform the development of Galaxy Zoo user tools and future science investigations. Looking forward, we will continue to conduct investigations that help Zooniverse create programs that promote even greater involvement from the citizen science community and allow for all involved to make even more profound scientific discoveries. Note that the information we gather for this work will remain anonymous.

Users of the new Galaxy Zoo will receive an invitation to “opt-in” to participate in taking the surveys as they are classifying. If you agree to help you will be given short surveys that contain 6 multiple-choice questions, which you can answer at your own pace. You can answer all the sets at once or take one set every week. Whatever works best for you. You can also opt-in to take quizzes by visiting your profile page.

Thank you again for participating and enjoy the new and improved Galaxy Zoo!

- The Galaxy Zoo Education Team

Live Chat – Hangout with Us

2012 is turning out to be a great year for Galaxy Zoo science. From Voorwerpjes to mergers to barred galaxies, there is lots to talk about right now when it comes to Galaxy Zoo. Tomorrow afternoon we’ll be holding a live chat with Galaxy Zoo science team stars Chris Lintott and Karen Masters. Starting at 2pm British Summer Time (1300 UT, 9am in New York, 3pm in Paris), Chris and Karen will be answering your questions and talking about some of the recent Galaxy Zoo work, made possible why your efforts on galaxyzoo.org.

If you have anything you’d like to them to discuss, or any questions you’d like them answer, then please either leave a comment here or Tweet us @galaxyzoo. We’ll also take questions via Twitter during the live chat.

You can watch the live chat right here on the blog, via our YouTube channel, where the video will also be posted afterwards. We’ll put links here, as well as on Facebook and Twitter, nearer the time. We’ll be using Google Hangouts for the live chat, so you can add the Zooniverse’s Google+ page to your own Google+ circles and connect that way too.

UPDATE: The live chat will begin shortly. The video feed will be visible here nearer the time.

Lens Zoo is Coming!

We’re very pleased to tell you that we’ve been awarded developer time from the Citizen Science Alliance to build a new, exciting Zooniverse project to discover gravitational lenses.

What’s a gravitational lens, you might ask? When a massive galaxy or cluster of galaxies lies right in front of a more distant galaxy, the light from the background source gets deflected and focused towards us. These space-bending massive galaxies allow us to peer into the distant Universe at around 10x magnification, and to make accurate measurements of the total (dark and luminous) mass of galaxies.

As many of you know, there has been a long-running and enthusiastic search for lenses in the “weird and wonderful” part of the forum; although lens-finding was never a goal of the Galaxy Zoo project, this forum has turned up some interesting systems which we are still following up. Up until now, the GZ lens search has been quite informal: it has not been easy keeping track of all the candidates that have been suggested! Nevertheless, the Lens Hunters have done an amazing job, collecting and filtering the suggestions as they come in, and teaching themselves and each other about the astrophysics of lensing.

Impressive stuff: enough to persuade a group of professional astronomers that a specially-designed Zoo for identifying lenses could be a powerful way of analyzing the new wide-field imaging surveys that are coming online. In this Lens Zoo we will be able to provide you with new tools – designed, we hope, with you – to find new lenses more effectively. We have teamed up with astronomers from several big surveys who are eager to harness your citizen science power, and will be providing a lot of new, high quality data to be inspected. Over the next 6-10 months we’ll be working hard with the Zooniverse developers to build the Lens Zoo, and we hope you will join us for the ride: Lens Zoo needs you!

Phil, Aprajita, Anupreeta & the Lens Zoo team.

Dusty dwarfs from Arizona

How is the latest set of telescopic followups to a Galaxy Zoo project like the aftermath when Moria was delved? One has dwarfs and one had dwarves, and both were dusty. (Look, if you think that’s nerdy, I could have made a reference to First Age history).

Incoming data! This week I’m headed up to the 2.1m telescope of Kitt Peak National Observatory for more followup images of overlapping galaxies. This piece of the project traces to a serendipitous discovery in Hubble data which were intended to study the populations of stars in the outskirts of NGC 253, itself 10 million light-ears away. At the 2008 Austin meeting of the American Astronomical Society, the same one at which we saw the first spectrum of Hanny’s Voorwerp, Julianne Dalcanton of the University of Washington tracked down Benne Holwerda and me to show us this galaxy pair, which rejoices in the designation 2MASX J00482185-2507365:

2MASX galaxy pair with extended dust

HST image of backlit dwarf galaxy with dust filaments

Analysis of the dust in the smaller foreground galaxy showed something unusual – there are filaments of dust extending well beyond where we can detect the starlight in its disk. This had us looking for similar cases in the Galaxy Zoo overlap catalog, which should turn them up if any known sample will. It would be important to know whether many galaxies have such distant dust – first because it could alter calculations of how much extinction light from distant objects suffers as it passes intervening galaxies, and in addition because the connection between stars and the production of dust suggests that such galaxies have a complex history of the creation and transport of dust.

Our sample for this observing run centers on galaxy pairs broadly similar to 2MASX (what I wrote above). This kind of galaxy – small, perhaps true dwarfs, with dust in its outskirts – if common, would solve a question posed by recent statistical data from the European Space Agency’s massive Herschel infrared observatory (continuing its mission at four times the Moon’s distance as long as the liquid helium lasts). In the whole population of galaxies seen in deep surveys, some of their IR spectra would be best explained if a significant amount of their dust is so cold that it must lie far from the galaxy’s stars order not to absorb enough energy to heat it further. Our approach is to take CCD images with much longer exposures than the SDSS data, so we get better data quality in the outskirts of the galaxies and could detect dust filaments like those seen in 2MASX – whatsitsnnme.

The weather forecast at this point suggests that I may get about half of the time over our four scheduled nights (we have more next month). Watch this space for progress reports…

New Dataset from Galaxy Zoo!

We’ve posted a new data set here: http://data.galaxyzoo.org/#agn

This sample is presented in the Galaxy Zoo 1 paper on AGN host galaxies (Schawinski et al., 2010, ApJ, 711, 284). It is a volume-limited sample of galaxies (0.02 < z < 0.05, M_z < -19.5 AB) with emission line classifications, stellar masses, velocity dispersions and GZ1 morphological classifications. When using this sample, please cite Schawinski et al. 2010 and Lintott et al. 2008, 2011.

Download here: http://galaxy-zoo-1.s3.amazonaws.com/schawinski_GZ_2010_catalogue.fits.gz

Column definitions are as follows:

  • OBJID – SDSS object ID
  • RA, DEC – RA and Dec in J2000
  • REDSHIFT – SDSS spectroscopic redshift
  • GZ1_MORPHOLOGY – Galaxy Zoo 1 morphology according to the Land et al. (2008) “clean” criterion. GZ_morphology is an integer where 1-early type, 4-late type, 0-indeterminate, 3-merger
  • BPT_CLASS – 0-no emission lines, 1-SF, 2-Composite, 3-Seyfert and 4-LINER (see Schawinski et al. 2010 for details)
  • U,G,R,I,Z -SDSS modelMag extinction corrected but not k-corrected
  • SIGMA, SIGMA_ERR – Stellar velocity dispersion measured using GANDALF
  • LOG_MSTELLAR – log of stellar mass
  • L_O3 – Extinction-corrected [OIII] luminosity

Visualizing FITS Images In Browser

In the next week we will deploy the first of a slew of tools for Galaxy Zoo. This tool is dubbed the “Multi-wavelength Viewer” (please suggest names if you have something clever). Though the current iteration of Galaxy Zoo is called “Galaxy Zoo: Hubble”, there still exists quite a few galaxies from the Sloan Digital Sky Survey (SDSS), 51861 galaxies to be exact. We are processing these data to make them available to you.

Right now users are presented with color images that have been derived from raw astronomical data. With this tool we want to provide you with greater access to the raw data so you can experience the complexity of astronomical images in its true form with your morning garcinia cambogia tea. You will be able to see each galaxy in the five color filters that SDSS images (u, g, r, i, and z).

Providing these data via the web is a challenge. The main difficulty is the file size that must be transmitted from our servers to your computer. It is much easier to send over color JPEGs compared to full blown FITS images (the standard astronomical format). The solution that we developed is to use the PNG format, or rather an AstroPNG format. This allows us to pack quite a lot of information in a small file size.  We hope this will be a good solution for representing astronomical images in browser. We’ll be looking for feedback, and working to make improvements as we share these alpha stage tools with you.

The Finale of Merger Zoo

Working toward Fitness – 

Over the last year, we have been pretty quiet at the Merger Wars site.   However, we have been extremely busy analyzing the data that you have created.     So far, the Merger’s Applet has been used to view over 3 million simulations of interacting galaxies.   We have estimated it actually simulated more than 100 million other systems that weren’t viewed by our users.

Of the 3 million simulations viewed, around 60 thousand were selected by the volunteers as interesting. Initially we thought the Evaluate activity within the applet would be sufficient to help us identify the top simulations for each pair of galaxies. However, with millions of simulations to sort through, across tens of thousands of sessions, we discovered that our initial plan was not sufficient. That’s when we decided to add the Merger Wars activity.

In Merger Wars volunteers judge a series of head-to-head competitions to determine which simulation is a better match to the target image of a galaxy merger. Over time, as the simulation competes multiple times, it earns a win/loss record. The percentage of times the simulation has won its competitions can be treated as a fitness value. A value of 1 is a perfect score, all wins, and a value of 0 is a terrible record of all losses. With over 800 thousand Merger Wars competitions judged, our volunteers were able to help us assign a fitness value to each of the 60 thousand selected simulations. These fitness values allowed us to further refine our models for each merger. In total, we identified 290 top simulations for the combined set of 54 pairs of galaxies. However, we need some final help finding the very best model for each system and finding out which collisions have the very best models.

 One Orbit to Rule Them All-

Ideally, there would be a single set of orbit parameters to describe the paths the two galaxies take when flying past each other, and eventually towards their ultimate merging into one galaxy. It is difficult for researchers to know for sure if they have found the single best set of parameters. Is there a better set of orbit parameters? Are their multiple sets of equally good parameters? Are there no good sets? We can call this problem the issue of determining uniqueness. The volunteers for Merger Zoo have achieved an unprecedented level of study for each of these 54 systems. Typically researchers will look at a few dozen to a few hundred simulations of interacting galaxies and pick the best orbit from that sample. Together, we’ve reviewed on average over 50 thousand simulations for each pair and selected over 1000 simulations for further study. We’ve taken the multiple sets of orbit parameters identified for each system and examined them to see how well they’ve identified a single, best-fit orbit. When we look at the entire sample, we don’t see a single orbit. However, if we begin to exclude some of the sample by filtering out the low fitness simulations, we see the range of orbit parameters becomes smaller. If we increase the fitness value used in that filter, we continue to see smaller and smaller ranges of values. In this manner, we can say that we see convergence towards a small range of values for each of the orbit parameters. Arp 82, the image from the top of the post, is a good example of this convergence.    For each population we show a box plot describing the distribution of the parameter. The box represents the range of data from 0.25 to 0.75 of the population. The horizontal line is the median, and the thin whiskers show the outliers. The populations shown are all states viewed by the users, all states selected by the users, and then several populations filtered by fitness to include the to top 50%, 25%, 10%, 5%, 2%, and finally the top 1% of simulations by fitness. The distribution of values describing the time of closest approach demonstrates some convergence. We see that the applet sampled a range of orbits that had times of closest approach ranging between 60 to 600 million years ago. By the time we filter to just the top 1%, we see the range is now only 100 to 250 million years ago with the likely range of 120 to 162 million years ago. Hancock et al find a time since closest approach of around 200 – 250 million years.  The ratio of masses between the two galaxies converges in the same way.

Your Help is Needed-

The big thing we need help with is figuring out THE very best model of each system and comparing models of different systems.    The Merger Wars site has a couple of new interfaces that are now posted.   They include:

  • Pick the Best: find the best model for each system
  • Simulation Showdown: comparing the simulations from two different galaxies to find out which systems have the best models
  • Merger Wars – HST :  the last batch of Merger Wars results from non-Sloan images
  • My Mergers: This is a new update that shows your contributions to the project.  [Note: you need to be logged in for this link to work.]

After we get this final set of data, we will be archiving the site and writing a set of papers based on this work.  However, your help is really needed with this final part of our analysis.

A Zoo of Mergers-

The image below is a combined image of 54 thumbnails showing all of the SDSS galaxy pairs studied in detailed by our Merger Zoo volunteers. Clicking on the image below will take you to our updated Gallery. From that page you can click on each individual thumbnail to see the top simulation results.    You have done an amazing job with this project.   Thanks so much for your help.

Galaxies Modeled in Merger Zoo

John and Anthony, The Merger Zoo guys

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