Tag Archive | Supernovae

Galaxy Zoo: Supernova Author Poster

Supernova Poster

For day one of the Zooniverse Advent Calendar we finally gave you the Galaxy Zoo 2 Author Poster. That project is complete, but there’s no reason we shouldn’t create similar thank-yous for the other Zooniverse projects. So here is the Galaxy Zoo: Supernova Author Poster!

13,400 individuals, who have taken part in the Supernova project to date, merged into an amazing image of the famous supernova 1987a. You can download the largest size (18MB), or the 2500-pixels version (6MB). There is also an equivalent author page on the Supernova website.

Radio Peas

Working with scientists in India, we have been awarded time on the Giant Metrewave Radio Telescope (GMRT) to study the radio properties of the Green Pea galaxies discovered by Galaxy Zoo users.  We hope to use this telescope to detect the first signs of radio emission from the Peas, establishing them as a new class of radio sources.

Why do we want to search for radio signals from the Peas?  The radio emission comes from remnant supernovae which can accelerate relativistic electrons that emit synchrotron radiation. So when we are detecting star forming galaxies in radio emission, we are finding signatures from these supernovae, which tell us about the stars that live (or lived) in the galaxy. Therefore, using the radio emission we can trace recent star formation activity in the galaxy.

We are particularly interested in these Green Peas, because they are the closest analogues to a class of vigorously star forming galaxies found in the early universe (known as Lyman Break Galaxies). These galaxies behaved very differently from star forming galaxies in the present day universe, and can help us to understand how galaxies formed in the early universe. Because Lyman Break Galaxies are so far away, Astronomers have not yet been able to detect radio emission from any of these galaxies individually. In contrast, the Peas are much closer and we have a good chance of being able to directly detect them in radio emission. Detecting this radio emission, and determining whether or not the radio emission from the Peas is like that in nearby star forming galaxies will help us to understand the nature of star formation in the youngest galaxies.

Supernova Zoo news

Thanks to all of you who participated in our second trial of the supernova hunt! As with our first trial in August, it was very successful, and kept our WHT observers, Jakob and Isobel, very busy – as you can see from their blogs! In the 3 days that we ran the trial, 2089 of you inspected over 2000 supernova candidates, answering more than 100,000 classification questions. The best of these were then passed to WHT for observation.

The first observing night had relatively poor observing conditions, but the second night was clear and plenty of zoo targets were observed. You can see a selection of the supernovae that you found and that were observed at WHT on the supernova zoo front page. Using the spectrograph on WHT, we were able to confirm these as supernovae and determine their types. We took spectra of more than 20 candidates identified by the zoo, and are now busy reducing and analysing that data.

Our plan now is to take the supernova hunt down for a short while, to make improvements to the tutorial and classification questions. Please do keep the feedback coming – the supernova zoo now has its own sub-forum where you can give us comments, and we will try to answer any questions that you might have. Our goal to have to supernova zoo support all of our Palomar Transient Factory supernova observing runs – and not just those at WHT – in the near future.

Thanks for all of your help!

Mark

Good morning

Almost all candidates on the list have been observed. Some were junk, but most were something real, like a supernova, an AGN, or a star. Now we only have to take some calibration data and burn the data to a dvd. I’m really looking forward to a few hours sleep. Good night!

/Jakob

The hunt goes on

The atmospheric conditions have degraded a bit, but we’re still collecting data.

Wiggles

Features of supernova spectra are very broad and therefore look like wiggles. Tonight we’re indeed lucky. All the spectra apears to have these wiggles in them. We’ve found a few type Ia supernova so far tonight. Apparently the selection of candidates via the supernova Zoo has been very effective.

/Jakob

Fantastic seeing

We’re lucky! Clear skies. The seeing is marvelous which means that we can obtain very good spectra.

/Jakob

Excellent conditions

The conditions are now excellent (seeing of 0.7 arcseconds). I hope it stays like this all night. This is really exciting!

/Jakob

Awaiting the sunset

We’re sitting in the control room of WHT awaiting the sunset. Before sunset we should take some calibration data and finalise the list of candidates. New candidates are sent to us by e-mail all the time. Tonight we’ll have a go at some candidates we didn’t observe yestereday or need to get an additional spectrum of. There are som very faint challenging targets we still haven’t decided whether to include or not. The wheather is much better to night. Almost no clouds at all. This is going to be an exciting night!

Typing of candidates

Using quick and dirty reductions we have begun identifying the candidates. We have found both type Ia and type II supernovae. It’s soon twilight and we have to take some calibration data before sunrise. Tomorrow night we’ll continue observing. We are pretty tired, so we’re looking forward to a good days sleep.

/Jakob