Monthly Archives: October 2014

The Anglo-Australian Telescope turns 40

On 16th October 1974, His Royal Highness the Prince of Wales formally opened the 3.9m Anglo-Australian Telescope (AAT, Siding Spring Observatory, NSW, Australia) for scientific operations. Hence the AAT (the telescope where I work) turned 40 last Thursday. We actually had some celebrations and events at the Australian Astronomical Observatory that day, including the release of this wonderful 8 min movie: Steve and the Stars,


The star of the show is Head Telescope Operator, Steve Lee, who has worked at the AAT for almost its entire 40 years of operation. Steve guides this video tour of working with the AAT, exploring how observational techniques have changed from the 1970s to today’s digital age, and the AAT’s exciting future pursuing more world-class discoveries. Famous astrophotographer David Malin co-stars the show. Some material taken from my astronomical time-lapses has been also used for this film.

After the public event for the “AAT 40th Anniversary Celebration” I couldn’t help myself and took this photo with all of us:

Photo taken at the end of the public event for the “AAT 40th Anniversary Celebration”, Thursday 16th Oct 2014. From left to right: Warrick Couch (AAO Director), Steve Lee (Head AAT Operators), Amanda Bauer (AAO Outreach Officer), David Malin (AAO famous astrophotographer) and Andrew Hopkins (Head of AAT Astro Science). Ah, yes, it is also me smiling as a little kid. Credit: Á.R.L.-S.

Happy 40th Birthday, AAT!

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Visions of a Total Lunar Eclipse within clouds

DP ENGLISH: This story belongs to the series “Double Post” which indicates posts that have been written both in English in The Lined Wolf and in Spanish in El Lobo Rayado.

DP ESPAÑOL: Esta historia entra en la categoría “Doble Post” donde indico artículos que han sido escritos tanto en español en El Lobo Rayado como en inglés en The Lined Wolf.

Last night half of the world (Eastern Asia, Australasia, Pacific and the Americas) enjoyed a total lunar eclipse. Again clouds were moving around over Sydney during all the day, I actually see the moon rising in the evening and in just few minutes moving into the clouds. The sky was almost completely covered when the eclipse started, at around 20:15 local time. I was fearing that, as it happened with the partial solar eclipse visible in Sydney last 29th April, I would not be able to get any useful image of the eclipse.

In any case, as I did for the occultation of Saturn by the Moon last May, I set up my telescope in the backyard and prepared everything for taking some photos of the event. Although I followed the eclipse almost completely, the clouds only allowed me to get good images in three occasions. These are the results:

Visions of a Total Lunar Eclipse within clouds.
8 October 2014 from Sydney. Data obtained using Telescope Skywatcher Black Diamond D = 80 mm, f = 600 mm, with a CANON EOS 600D at primary focus. The Red Moon compiles 40 frames taken at 1/3 s & ISO 800. Stacking using Lynkeos software, final processing with Photoshop. Credit: Á.R.L-S. (AAO/MQ)


It is not too much but I hope you like it. I will wait for the next total lunar eclipse to try to get the time-lapse sequence of all the event.

Dissecting galaxies of the Local Universe with the CALIFA survey

DP ENGLISH: This story belongs to the series “Double Post” which indicates posts that have been written both in English in The Lined Wolf and in Spanish in El Lobo Rayado.

DP ESPAÑOL: Esta historia entra en la categoría “Doble Post” donde indico artículos que han sido escritos tanto en español en El Lobo Rayado como en inglés en The Lined Wolf.

The Calar Alto Legacy Integral Field spectroscopy Area (CALIFA) survey is a project that aims to obtain data of around 600 nearby galaxies using the PMAS (Potsdam Multi Aperture Spectrophotometer) instrument of the 3.5m Telescope at the Calar Alto Observatory (Almería, Spain). The CALIFA survey combines the advantages of two observational techniques: imaging (that provides detailed information on galactic structure) and spectroscopy (that reveals the physical properties of galaxies, such as their kinematics, mass, chemical composition or age). The CALIFA survey makes use of the Integral Field Spectroscopy (IFS) technique, that allows obtaining at the same time around a thousand of spectra per galaxy, hence getting simultaneously imaging and spectra of astronomical objects.

A galaxy is “dissected” in thousands small regions, each one having its particular spectrum (wavelength) when using Integral Field Spectroscopy (IFS) techniques. The result is getting a datacube: two axes (x and y) possess the spatial information (the image of the galaxy, which can also be separated in several colours) and the third axis (wavelength) keep the spectroscopic information. Credit: Marc White (RSAA-ANU).

The CALIFA Project allows not only to inspect the galaxies in detail, but it also provides with data on the evolution of each particular galaxy with time: how much gas and when was it converted into stars along each phase of the galaxy’s life, and how did each region of the galaxies evolve along the more than ten thousand million years of cosmic evolution

Thanks to these data, astronomers of the CALIFA team have been able to deduce the history of the mass, luminosity and chemical evolution of the CALIFA sample of galaxies, and thus they have found that more massive galaxies grow faster than less massive ones, and that they form their central regions before the external ones (inside-out mass assembly). CALIFA has also shed light on how chemical elements needed for file are produced within the galaxies or on the physical processes involved on galactic collisions, and it has even observed the last generation of stars still in their birth cocoon.

CALIFA “panoramic view” (also CALIFA’s “Mandala”) representation, consisting of the basic physical properties (all of them derived from the CALIFA datacubes) of a subsample of 169 galaxies extracted randomly from the 2nd Data Release. It shows 1) broad band images (top center), 2) stellar mass surface densities (upper right), 3) ages (lower right), 4) narrow band images (bottom center; emission lines: Hα [N II] 6584 Å, and [O III] 5007 Å), 5) Hα emission (lower left) and 6) Hα kinematics (upper left). The CALIFA logo is placed at the central hexagon. Credit: R. García-Benito, F. Rosales-Ortega, E. Pérez, C.J. Walcher, S. F. Sánchez & the CALIFA team.

Today, Oct 1st, the CALIFA Team (and I’m part of it) has released 400 IFS datacubes for 200 nearby galaxies, the 2nd Data Release (DR2). The data are publically available and can now be used by astronomers around the world. The second CALIFA Data Release provides the fully reduced and quality control tested datacubes of 200 objects in two different spectral configurations. Each datacube contains ~1000 independent spectra, thus in total the CALIFA DR2 comprises ~400,000 independent spectra (~1.5 millon after cube reconstruction). The scientific details of the data included in the CALIFA DR2 are described in this scientific paper lead by the Spanish astronomer Rubén García-Benito.

More information about the CALIFA survey and its DR2:

– Calar Alto Observatory Press Release: http://www.caha.es/an-unprecedented-view-of-two-hundred-galaxies-of-the-local-universe.html

– Scientific paper about CALIFA DR2: García-Benito et al. (2014): http://arxiv.org/abs/1409.8302

– CALIFA webpage: http://www.caha.es/CALIFA/public_html

– CALIFA DR2 webpage: http://califa.caha.es/DR2