Monthly Archives: May 2016

A year since the “Multiwavelength Dissection of Galaxies” Conference

I cannot believe a FULL YEAR has already gone since the “Multiwavelength Dissection of Galaxies” Conference happened. And I have never found the time to just describe how much work this was for me, and at the success of this meeting. At least let me share today the article I wrote for “The Observer”, the AAO Newsletter.

The Southern Cross Astrophysics Conferences, which are jointly supported by the Australian Astronomical Observatory (AAO) and the CSIRO Astronomy and Space Science (CASS), are held annually around Australia with the aim of attracting international experts with wide ranging skills to discuss a particular astrophysical topic. The conference “Multiwavelength dissection of galaxies”, which was held at the Crown Plaza Hotel in  Coogee Beach, Sydney between 24th – 29th May 2015, was the 8th of the Southern Cross Conference Series. This Conference focused on galaxy evolution, combining resolved optical/near-infrared integral field spectroscopy data with other multiwavelength properties (from X-ray to radio) of nearby galaxies plus giving the view of what is known in our Milky Way.

Poster of the Conference "Multiwavelength Dissection of Galaxies".

Poster of the Conference “Multiwavelength Dissection of Galaxies”.

Indeed, the number of studies of galaxies using integral field spectroscopy (IFS) is rapidly increasing as a consequence of surveys such as ATLAS-3D, CALIFA, SAMI (that is conducted at the AAT), or MANGA. IFS techniques allow to spatially resolve internal properties of galaxies with unprecedented detail, and therefore they are providing key clues for understanding the structural components of galaxies, their star-formation activity, kinematics, stellar populations, metal distribution, and nuclear activity, as well as how galaxies evolve with time. Nevertheless, for a complete picture of how galaxies work it is crucial to use other multi-wavelength results, targeting galaxies in X-ray, ultraviolet, infrared, and radio frequencies. In particular, HI radio-surveys such as HIPASS, LVHIS, THINGS, Little-THINGS, ALFALFA, HALOGAS or WALLABY are essential to trace the neutral gas content of galaxies, as the 21 cm HI radio data provide key information about how the cold gas in converted into stars and galaxy dynamics. At the same time we are notably increasing our knowledge of the structure and composition of the Milky Way. This is possible thanks to the combination of very detailed observations of individual stars (such those coming from the RAVE survey conducted at the 1.2m UKST or the on-going GALAH survey at the AAT using the new high-resolution HERMES spectrograph), detailed analyses of Galactic nebulae, large field studies of the interstellar medium, and surveys searching for the diffuse gas with and around our Galaxy.

Hence, the aim of the “Multiwavelength dissection of galaxies” Conference was to bring together international experts in both Galactic and extragalactic astronomy to discuss the different components of a galaxy: stars, gas, dust, and dark matter, and where these components are found within and around galaxies, from both an observational (from radio to X-rays, but with a fundamental optical IFS component) and a theoretical point of view (from the most recent simulations of galaxy assembly to models reproducing the chemical evolution of galaxies), with the final objective of getting a better understanding on the processes that rule the evolution of the galaxies.

Conference Photo with the majority of the participants to the “Multiwavelength Dissection of Galaxies” meeting, 24th - 29th  May 2015. The background is an image of the Southern sky showing the Southern Cross and the Pointers. Credit: Conference Photo: Andy Green (AAO), Background image & composition: Ángel R. López-Sánchez.

Conference Photo with the majority of the participants to the “Multiwavelength Dissection of Galaxies” meeting, 24th – 29th May 2015. The background is an image of the Southern sky showing the Southern Cross and the Pointers. Credit: Conference Photo: Andy Green (AAO), Background image & composition: Ángel R. López-Sánchez.

Around 120 astronomers all around the globe attended to this Conference. In five days we had 94 talks, including 27 invited talks and a Summary talk, and 26 poster contributions. Highlight invited talks were given by Rosemary Wyse (The Structure of the Milky Way), Naomi McClure-Griffiths (Neutral gas in and around the Milky Way), Baerbel Koribalski (Diffuse gas in and around galaxies), Christy Tremonti (Measuring Gas Accretion and Outflow Signatures with MaNGA), César Esteban (Ionized gas in the Milky Way), Evan Skillman (The Chemical Properties of the ISM of Nearby Galaxies), Sarah Martell (Introduction to the GALAH Survey), Geraint Lewis (Galactic Archeology in the Local Group), Alessandro Boselli (The dust emission properties of nearby galaxies after Herschel), Jakob Walcher (News about the interstellar medium in galaxies from the CALIFA survey), Stas Shabala (Resolving the mysteries of AGN feedback:radio jets, galaxies and citizen science), Joss Bland-Hawthorn (Near Field Cosmology), Martin Asplund (The Gaia-ESO survey), Richard Bower (The EAGLE Universe), Lisa Kewley (SAMI Science) and Molly Peeples (A Multiwavelength View of the Circumgalactic Medium).

We also organised a “Poster Contest”: participants were asked to vote for their 2 favourite posters, and they got a short (10 minutes) talk during the last session of the Conference. The winners were two PhD students: Christina Baldwin (Macquarie University, Australia, with the poster “Early-Type Galaxy Stellar Populations in the Near-Infrared”) and Manuel Emilio Moreno-Raya (Universidad Complutense Madrid and CIEMAT, Spain, with the poster “Dependence of SNe Ia absolute magnitudes on the host galaxies elemental gas-phase abundances”).

We have compiled all scientific presentations at the Conference Webpage:

Furthermore, participants were very active in Twitter, that followed the hashtag of the Conference #MDGal15, allowing a wider diffusion of the main results speakers were presenting. We have also compiled all tweets in a Storify for each day, they are available in our website.

Besides the scientific talks, participants enjoyed the social events we organised for the Conference, including a Welcome Cocktail Cruise on Sunday 24th May (delegates enjoyed not only the great views of Sydney Harbour but also a starry sky and the famous ViVID Lights Sydney Festival), a Wine Tasting event on Tuesday 26th, an outdoors barbecue and a visit to Sydney Observatory and Stargazing on Wednesday 27th May, and the Conference Dinner on Thursday 28th May, which was held at the Spanish restaurant “Postales” in famous Martin Place, Sydney. Furthermore, the AAO organised the Public Event “The Story of Light: The Astronomer’s Perspective” on Sunday 24th May at the Powerhouse Museum (Sydney). This event, which was fully booked, was included as part of the ViVID Festival and connected the International Year of Light 2015 with our Conference.

Overall, we considered it was a great Conference and some important and controversial research topics were actually discussed during those five days, generating new ideas and projects, and many new collaborations between participants (even between Galactic and extragalactic astronomers) started there.

Finally, I would like to thank the impeccable organisation of the staff at Crown Plaza Hotel, as everything worked very smoothly and we didn’t have any problems at all during our Conference. In particular, coffee breaks and lunches were very well attended, and we really enjoyed a great quality food. Of course, I also must thank all the members of the LOC and the SOC committees for their invaluable help organising this Conference. In particular, I would like to thank Helen Woods (AAO) for her enormous effort and Andrew Hopkins and AAO’s Director, Warrick Couch, for their strong support to this meeting.

Spiral galaxy NGC 4027 with AAT: an outreach exercise

During this week I’m curator of the @astrotweep, a Twitter account that each week features an astronomer or planetary scientist taking about their research, science and life. I’m having a lot of fun with it, although I have to recognize it is extra work.

I chose to do it this week because there are some few things happening. In particular, I’m supporting observations at the Anglo-Australian Telescope (Siding Spring Observatory, NSW, Australia) using the 2dF / HERMES instruments. I thought it would be nice to be tweeting life how observations are doing. And that is precisely what I’ve doing today.

On top of that, “this morning” I had an idea. As we always have some “free time” at the AAT after completing the “2dF first night setup” (1) I decided to observe a nice bright deep sky object and get a nice image with the AAT. I was starting to search for a suitable target, but then I though, why don’t I ask the public what do they want to observe?

After consulting with my supervisors and getting the OK to do this, I initiated a poll in both @astrotweeps and @AAOastro asking the public to vote for one of the four following astro objects:

  1. The elliptical galaxy NGC 2865.
  2. The planetary nebula NGC 4361.
  3. The warped and almost edge-on spiral galaxy ESO 510-G13.
  4. The barred spiral galaxy NGC 4027.

For around 8 hours people were casting their vote, we received 153 unique votes in total combining the @AAOastro and the @astrotweets accounts.

And the winner (2) was… the barred spiral galaxy NGC 4027!

But surprises didn’t end here. In the afternoon, when I was starting to prepare the instruments for the night (I’m conducting observations remotely from Sydney), I explained to astronomers and technicians at the AAT what we were doing. Rob Paterson, our afternoon technician, then told me “Do you know we already have the new CCD camera installed in 2dF and just waiting for testing it?

Let me explain why I was so excited when I heard this. For years the 2dF instrument has had an auxiliary camera, the FPI camera, that we use for properly positioning 2dF in the requested field. Rarely it has been used for science, as it is just a 516×516 pixels camera without filters. Occasionally I have also used it for getting some images of deep sky objects. But, as it has no filters, I had to get the color of the images elsewhere, usually taking archive data taken with other telescopes. But the new CCD camera in 2dF does have filters!

Rob phoned Steve Lee, the head of the Night Assistants at the AAT, and with Bob Dean the three of them managed to prepare CACTI (that is the name of the new camera) to have it ready for us.

Although there is still a lot to be done and tests to be conducted, the very first images I got this evening are quite promising. Here is the final result:

Spiral galaxy NGC 4027 located at around 75 million light years in Corvus (The Crow). This barred spiral galaxy, also identified as Arp 22, is identified as a peculiar galaxy by the extended arm, thought to be the result of a collision with another galaxy millions of years ago. This image is the “First Light” of the new CACTI camera in 2dF @ 3.9m Anglo-Australian Telescope. Color image using B (4 x 120 s, blue) + V (6 x 60 s, green) + R (6 x 60 s, red) filters. The data were taken on 11 May 2016 as part of an “outreach exercise” via social media. Click here to get a higher resolution image. Credit: Ángel R. López-Sánchez (AAO/MQ) & Steve Lee, Robert Paterson & Robert Dean (AAO). Night assistant at the AAT: Andre Phillips (AAO).

Note that this image, that actually is the “first light” of the CACTI camera, only combines 6 minutes in V and R and 8 minutes in B, that is, it is not deep at all. Furthermore not extra calibrations were taken (some flatfield images would have been nice). The deep image obtained by the 3.6m NTT telescope (ESO La Silla Observatory, Chile) provides many more details and resolution… but of course they were using the EFOSC instrument, which was specifically designed for deep imaging in optical filters. And the  image of NGC 4027 obtained by David Malin (AAO) using photographic plates at the AAT in 1982 is much more colorful.

But I still think it is a pretty result, particularly as this new image of NGC 4027 was obtained as a completely improvised “outreach exercise” using social media, in which 153 people voted for their favorite object to be observed at the 3.9m Anglo-Australian Telescope.

I really hope to repeat this exercise soon.

(1) A 2dF Plate must be configured with a scientific field, that is, allocating ~350 optical fibres to different objects in the sky. This takes ~ 20-30 minutes.

(2) Just to provide the details of the votes, see table below:

OBJECT    @Astrotweeps   @AAOastro       COMBINED

NGC 2865               5                  4                    9    ( 6% )

NGC 4361            36                   9                   45   (29%)

ESO 510-G13      36                  7                     43   (28%)

NGC 4027           36                20                    56   (37%)

TOTAL              113                 40                   153

Come to our ViVID Sydney 2016 Astronomy Event!

During the last months I’ve been working hard to organize an Astronomy event during the famous ViVID Sydney festival, 27th May – 18th June 2016. With the title “The Story of Light – Deciphering the data encoded on the cosmic light”, this science communication event is presented by the Australian Astronomical Observatory (AAO). It follows our sold-out Event “The Story of Light – The Astronomer’s Perspective” for ViVID Sydney 2015, that was originally planned as part of the International Multiwavelength Dissection of Galaxies  Conference I organized last year (now I’m realizing I never talked about this here…).

Banner image of the “The Story of Light – Deciphering the data encoded on the cosmic light” event on Sunday 29th May 2016. The image represents a multiwavelength photo of the galaxy M101 (center), the 2dF Galaxy Redshift Survey (AAO, left and right), the equations of the stellar interiors, and a background of 1s and 0s codifying astronomical data. Credit of the composition: Ángel R. López-Sánchez. Credit of the 2dFGRS: AAO, Credit of image of M 101: Ángel R. López-Sánchez.

Banner image of the “The Story of Light – Deciphering the data encoded on the cosmic light” event on Sunday 29th May 2016. The image represents a multiwavelength photo of the galaxy M101 (center), the 2dF Galaxy Redshift Survey (AAO, left and right), the equations of the stellar interiors, and a background of 1s and 0s codifying astronomical data. Credit of the composition: Ángel R. López-Sánchez. Credit of the 2dFGRS images: AAO. Credit of image of M 101: Ángel R. López-Sánchez.

This event will be held at the PowerHouse Museum (Sydney) on Sunday 29th May, 2:00-3:30pm. Four professional astrophysicists will discuss what astronomy provides in the context of exploiting big data:

  • The light and light-based technologies developed in Australian astronomy for both optical and radio telescopes; the tools, platforms, and techniques used for data analysis and visualization
  • How astronomers create simulation data
  • How some of these techniques are being used in other research areas and;
  • The major scientific contributions toward our understanding of the Universe.

Indeed, for decades, astrophysicists have developed novel approaches to exploring the light of the Cosmos, most recently through data-intensive techniques, analytics and visualization tools to extract the information collected by extremely sensitive telescopes and instruments. Astronomers have been pioneers in developing data science techniques to make sense of this huge data deluge, many of which are now used in other areas.

There is no need to say that I’m very excited about this new ViVID Sydney event, not only because of all the effort I’ve already put into this but also because I’m one of the astronomers in the panel! I’ll be talking about optical Astronomy, discussing the importance of the optical spectroscopy, how it is done with the AAO telescopes, and describing some of their current a future instruments.

But that is not all. I’m also extremely happy to do this with four great astronomers and science communicators:  Vanessa Moss (CAASTRO/Univ. of Sydney), who will talk about radioastronomy & big Data and the ASKAP,  Luke Barnes (Univ. of Sydney), discussing simulating, analysing and visualisation of astronomy data, and Elizabeth Mannering (AAO/ICRAR), who will describe the importance of Data Archive, Virtual Observatories, and the ASVO project at the AAO. On top of that, the host of our event is the famous astronomer and science communicator Alan Duffy (Swinburne University). I’m sure it is going to be quite an experience.

This event, however, is not free, as a ticket for the entry to the PowerHouse Museum ($15  for adults, $8 concession) is needed. You can get your tickets in the Event Webpage of the PowerHouse Museum.

For more information and a full description of the speakers, please check our AAO webpage. The link to this event in the ViVID Sydney website is here.

I hope to see you there!