LBT takes a close look at a lava lake on Jupiter's moon Io

With the first detailed observations through imaging interferometry of a lava lake on a moon of Jupiter, the Large Binocular Telescope Observatory places itself as the forerunner of the next generation of Extremely Large Telescopes. 

Io, the innermost of the four moons of Jupiter discovered by Galileo in January 1610, is only slightly bigger than our own Moon but is the most geologically active body in our solar system. Hundreds of volcanic areas dot its surface, which is mostly covered with sulfur and sulfur dioxide. 

The largest of these volcanic features, named Loki after the Norse god often associated with fire and chaos, is a volcanic depression called patera in which the denser lava crust solidifying on top of a lava lake episodically sinks in the lake, yielding a rise in the thermal emission which has been regularly observed from Earth. Loki, only 200km in diameter and at least 600 million km from Earth, was, up to recently, too small to be looked at in detail from any ground based optical/infrared telescope.

Io seen by LBT (left) on 2013 December 24 (left) compared to a USGS map (right) based on images from NASA’s Voyager 1 and 2 missions (acquired in 1979) as well as the Galileo orbiter (1995-2003).

Credit: LBTO-USGS

With its two 8.4 m mirrors set on the same mount 6 m apart, the Large Binocular Telescope (LBT), by combining the light through interferometry, provide images at the same level of detail a 22.8 m telescope would reach. Thanks to the Large Binocular Telescope Interferometer (LBTI), an international team of researchers was able to look at Loki Patera, revealing details as never before seen from Earth; their study is published today in the Astronomical Journal (link here).

The LBT image of Loki Patera (orange) laid over a Voyager image of the volcanic depression.The emission (in orange color) appears spread out in the north-south direction due to the telescope point-spread function; it is mainly localized to the southern corners of the lake. Credit: LBTO-NASA

Read the whole story here

First paper from the LEECH survey...

Astronomers Probe Inner Region of Young Star and its Planets

Taking advantage of the unprecedented sensitivity of the Large Binocular Telescope in southeastern Arizona, an international team of astronomers has obtained the first results from the LEECH exoplanets survey. The findings reveal new insights into the architecture of HR8799, a "scaled-up" version of our solar system 130 light-years from Earth.

The planetary system of HR 8799. 

The observations mark the first results of a new exoplanet survey called LEECH (LBT Exozodi Exoplanet Common Hunt), and are published today in the journal Astronomy & Astrophysics (http://www.aanda.org/10.1051/0004-6361/201425185).

If you want to know more, follow this link!

A Monster Black Hole Discovered at Cosmic Dawn

Using data from the 2.4 meter Lijiang Telescope (LJT) in Yunnan China, the 6.5-meter Multiple Mirror Telescope (MMT), and the 8.4m Large Binocular Telescope (LBT) in Arizona, USA, the 6.5m Magellan Telescope in Las Campanas Observatory, Chile, and the 8.2m Gemini North Telescope in Mauna Kea, Hawaii, USA, an international team led by Prof. Xue-Bing Wu at Peking University discovered a new quasar, with its central black hole mass of 12 billion solar masses and the luminosity of 420 trillion solar luminosity, at a distance of 12.8 billion light years from the earth. This is the brightest quasar ever discovered in the early universe, powered by the most massive black hole yet known at that time. 

The discovery of this quasar, named SDSS J0100+2802, marks an important step in understanding how quasars, the most powerful objects in the universe, have evolved from the earliest epoch, only nine hundred million years after the Big Bang, close to the end of an important cosmic event that astronomers referred to as the “epoch of reionization”: the cosmic dawn when light from the earliest generations of galaxies and quasars were thought to transformed the Universe, ending the “cosmic dark ages”. This discovery is also a surprise: how can a quasar so luminous, and a black hole so massive, form so early in the history of the Universe, at an era soon after the earliest stars and galaxies have just emerged? This research result will be published in the scientific journal “Nature” on Feb 26, 2015.

Discovered in 1963, quasars are the most powerful objects beyond our Milky Way Galaxy. It shines itself as its central supermassive black hole actively accretes surrounding materials. Thanks to the power new generation of digital sky surveys, astronomers have discovered more than 200,000 quasars, ages ranging from 0.7 billion years after the Big Bang to today, with corresponding redshifts up to 7.085. Due to the expansion of the universe, objects are moving away from us. Wavelength of light received by us is larger than that of the originally emitted light. Redshift is defined as the ratio of the wavelength difference to the original wavelength.

The newly discovered quasar SDSS J0100+2802 is the one with the most massive black hole and the highest luminosity among all known distant quasars (Credits: Zhaoyu Li/Yunnan Observatory. The background photo, provided by Yunnan Observatory, shows the dome of the 2.4meter telescope and the sky over it)

High redshift traces structure and evolution of the early universe. However, despite of their high luminosity, they still appear faint due to their large distance away from us, and they are extremely rare on the sky, which make them very difficult to find. Among all the discovered 200,000 quasars, only 40 are 12.7 billion light year away with redshift higher than 6.

In recent years, a team led by Xue-Bing Wu, a professor of the Department of Astronomy, School of Physics at Peking University and the associate director of the Kavli Institute of Astronomy and Astrophysics, have developed a method to effectively select quasars with redshift higher than 5 based on optical and near-infrared photometric data, in particular, using data from the Sloan Digital Sky Survey and NASA’s Wide-Field Infrared Explorer (WISE) satellite. Then with spectroscopic observations, they have systematically discovered a large number of new high redshift quasars. SDSS J0100+2802 is one among them but has the highest redshift in their sample, and one of the most distant quasars discovered.

The first optical spectrum obtained on Dec. 29, 2013 by the 2.4m LJT, shows that it is likely a quasar with redshift higher than 6.2. Active international collaborations allowed this team to further gather data from the MMT, the LBT, the Magellan Telescope and the Gemini Telescope. By carefully analyzing these data, the team confirmed SDSS J0100+2802 as a quasar with redshift of 6.3 and estimated its intrinsic properties. At 420 trillion solar luminosity, this new quasar is 7 times brighter than the most distant quasar known (which is 13 billion years away). It harbors a black hole with mass of 12 billion solar masses, proving it to be the most luminous quasar with the most massive black hole among all the known high redshift quasars. By comparison, our own Milky Way Galaxy has a black hole with a mass of only 3 million solar masses at its center; the black hole that powers this new quasar is four thousand times heavier.

The combined optical/near-infrared spectrum of J010012802 and the fitting of the MgII line. Main panel, the black line shows the LBT optical spectrum and the red line shows the combined Magellan and Gemini near-infrared J,H,K-band spectra (from left to right, respectively). Inset, fits of the MgII line (with FWHM of 5,130 +/- 150 km/s) and surrounding Fe II emissions

“This quasar is very unique. We are so excited, when we found that there is such luminous and massive quasar only 0.9 billion years after the Big Bang. Just like the brightest lighthouse in the distant universe, its glowing light will help us to probe more about the early universe.” said Xue-Bing Wu.

“This quasar was first discovered by our 2.4 meter telescope in Lijiang, Yunnan, China.” said Feige Wang, a PhD graduate student from Peking University who participated in the selection and identification of the quasar. “It is also currently the only one quasar with redshift larger than 6 ever discovered by a 2-meter telescope in the world. We are very proud of it.”

“Discovery of this ultra-luminous quasar presents a major puzzle to the theory of black hole growth at early universe. How can supermassive black holes grow so quickly when the Universe was so young? What is the relationship between this monster black hole and its surrounding environment, including its galaxy host? This ultra-luminous quasar with a 12 billion solar mass black hole provides a unique laboratory to the study of the mass assembly and galaxy formation around the most massive black hole at early Universe.” Added Prof. Xiaohui Fan from Steward Observatory, the University of Arizona who is part of this team.

For Christian Veillet, Director of the Large Binocular Telescope Observatory (LBTO), this discovery demonstrates both the power of international collaborations and the benefit of using a variety of facilities spread throughout the world.

“This result is particularly gratifying for LBTO, which is well on its way to full nighttime operations,” said Dr. Veillet. “While in this case, the authors used two different instruments in series, MODS1 for visible light spectroscopy and LUCI1 for near-infrared imaging, LBTO will soon offer a pair of MODS and a pair of LUCIs that can be used simultaneously, effectively doubling the number of observations possible in clear skies and ultimately creating even more exciting science”.

To further unveil the nature of this remarkable quasar, and to shed light on the physical processes that led to the formation of the earliest supermassive black holes , this research team will carry out further investigations on this quasar with more international telescopes including the Hubble Space Telescope and the Chandra X-ray Telescope.

The LBT LUCI1 K-band image of J010012802. The size is 10"x10". 
The horizontal and vertical axes denote the offsets in Right Ascension (RA) and in Declination (DEC). 
The image, with seeing of 0.40", shows a morphology fully consistent with a point source.

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Reference:

An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
Xue-Bing Wu, Feige Wang, Xiaohui Fan, Weimin Yi, Wenwen Zuo, Fuyan Bian, Linhua Jiang, Ian D. McGreer, Ran Wang, Jinyi Yang, Qian Yang, David Thompson & Yuri Beletsky

Nature 518, 512–515 (26 February 2015) doi:10.1038/nature14241

First AO light on LUCI2

It is commissioning time for the diffraction limited mode of LUCI2, the near infrared imager and multi-object spectrograph which saw first light in seeing-limited mode back in November 2013.

Much work was performed during day time on the NCPA (non-common path aberrations) correction starting on January 19, 2015, to be ready for the first night of on-sky observing on January 26. Unfortunately, clouds and snow falls were followed on the 27th by yet another overcast night.

On the night of the 28th, a 2-hr gap of clear sky between waves of heavy clouds led to first light on LUCI2 in AO mode. With a seeing of about 1arcsec, the loop on the bright star HIP 15925 (6th mag) was closed the star imaged with LUCI2 and the FLAO system working with NCPA correction in HeI (1.1µm), FeII (1.6µm), and Br_gamma (2.2µm) filter bands. 

The Strehl ratios achieved at first light were 45% at 1.1µm, 75% at 1.6 and 2.2µm wavelength (see a very preliminary analysis on the pictures below), a tribute to the quality of the preparatory daytime work! 

There is obviously much work ahead over the next months to get the system ready for regular observations, but these first results augur well for the final performance of LUCI2 in diffraction-limited mode, and eventually of LUCI1 once equipped with its AO-compatible camera toward the end of the year!

LUCI2-AO commissioning work is led by W. Seifert (LUCI) and S. Esposito (AO)

First LBT interferometry science paper

The first designs of what became the Large Binocular Telescope (LBT) were drawn more than 25 years ago, at a time when its observing modes were also conceptually defined, enabling the spatial resolution of a 23-m telescope while providing the versatility of a pair of 8-m telescopes. An important step was recently taken with the publication of the first refereed science paper using the NASA-Headquarters funded LBT Interferometer (LBTI).

LBTI (green and silver structure in the center of the picture) between the two 8.4m mirrors of LBT

LBTI coherently combines the two LBT beams to achieve the 23-m resolution the observatory offers today as a precursor to the Extremely Large Telescopes (ELTs) currently in development and hopefully operational in the mid-to-late 2020s. 

The published study reports LBTI's first test observations of stardust, in this case around a mature, sun-like star called eta Corvi known to be unusually dusty. According to the science team, this star is 10,000 times dustier than our own solar system, likely due to a recent impact between planetary bodies in its inner regions. The surplus of dust gives the telescope a good place to practice its dust-detecting skills.

The results show that the telescope works as intended: a tribute to the many who contributed to the development of the observatory.

Find more on this landmark paper in LBTO's history by reading the NASA-JPL press release entitled Telescope To Seek Dust Where Other Earths May Lie, issued on January 20, 2015. 

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The article

FIRST-LIGHT LBT NULLING INTERFEROMETRIC OBSERVATIONS: WARM EXOZODIACAL DUST RESOLVED WITHIN A FEW AU OF η Crv

D. Defrère, P. M. Hinz, A. J. Skemer, G. M. Kennedy, V. P. Bailey, W. F. Hoffmann, B. Mennesson, R. Millan-Gabet, W. C. Danchi, O. Absil

is published in the Astrophysical Journal and available online here.

doi:10.1088/0004-637X/799/1/42

ARGOS GLAO closed the loop

The lasers of the ARGOS Ground Layer Adaptive Optics (GLAO) system were propagated from the two sides of the LBTO telescope for the first time on November 5, 2013. See the previous post on this topic for more information.   

Slightly more than one year later, at the end of November 2014, the LBTO adaptive optics was locked on the three laser guide stars of the ARGOS constellation on the right side of the telescope, achieving an impressively good correction on the whole field of LUCI2. 

The three LGS wavefront sensors in closed loop

0.3 to 0.4 arc-second images in J, H and K were obtained using GLAO correction from 0.7 to 1 arc-second uncorrected seeing. The best corrected images reached 0.22 arc-seconds in Ks, bringing a factor 4 PSF improvement over natural seeing. 

This animation blinks between a pair of uncorrected and ARGOS-corrected images 

of NGC 2419 (~3.6'x3.6') with LUCI2

A close-up (~18"x10") on NGC 2419 - 100s - H band 
0.8-0.9" uncorrected PSF, 0.3"-0.4" GLAO corrected

This is a very important step in the development of ARGOS, auguring well for the final performance of the LUCI1-LUCI2-ARGOS combination!

There is still much work to be done with ARGOS: fine-tuning and streamlining operations in the first half of 2015, installing the left side wave front sensors on the telescope in the summer of 2015, and commissioning them in the last months of 2015. The whole system will then be integrated to the observing environment and extensively tested in binocular mode, with a release to science currently envisioned for mid-2016. 

Kudos to the whole ARGOS team and many thanks to the LBTO staff and the laser spotters for a great support!

More information on the ARGOS project is available here.

Shutdown is over. Restarting the observatory...

Every summer, during monsoon season, the observatory is shutting down to perform a mix of maintenance tasks and improvement/development work which all require the telescope to be inoperative for an extended period of time, therefore precluding any observation.With short nights and the weather in average much worse than during the rest of the year, July/August is the preferred time. 

The 2014 shutdown lasted from July 9 to August 29 and the observatory is now in restarting mode for a couple of weeks. Science will start again on September 17 (see the 14B schedule here).

On the long list of things to do during shutdown, taking care of our two primary mirrors remains a big endeavor. Every year, we realuminize one of them and wash the other. As there are no mirror covers (yet), the main mirrors are more exposed to an environment which is not very forgiving (moths, pollen, dust, ...) than at other observatories. This year, the right mirror (DX) got a new coating and the left (SX) went through a good cleaning.

Washing DX before stripping the aluminum (Jul 28)

The DX main mirror is now ready for aluminizing (Jul 29) 

Washing SX (Aug 20)

The telescope has now two clean eyes! 

The realuminizing  went went very smoothly and the coating on DX is one of the best so far. SX is clean and shiny. As the moth population is smaller than usual this summer, both should stay clean for quite some time. You can see pictures of other phases of the realuminizing process here (2013 shutdown).

Much work has been done on various subsystems of the telescope. To cite only a few: improvement of mirror ventilation and instrument cooling system, installation of new oil catchment, roof sealing, addition of flexible vacuum lines for LINC NIRVANA, maintenance and improvement of AGW (Acquisition, Guiding, and Wavefront sensing units) #1 and #2, including the addition of a tip-tilt sensor for ARGOS on AGW2 (right side),  ...   

Preparing for on-site fitting of the newly built oil pans

Oil pans are now installed under the C-rings 

Working on one of the many cooling systems on level 4 , under the telescope level of the enclosure 

The two shiny hoses hanging from the telescope structure to the enclosure wall will be used by LINC NIRVANA to  cool down their detectors.

On the instrument side, the LBCs went through their annual maintenance. LUCI1, which had been unavailable due to various issues for a good part of last semester, was brought back to life and the tests so far have not shown any problem. Work on PEPSI by the IAP team continued and we should be able to announce soon the first light from the VATT through an optical fiber laid underground between the two observatories. Stay tuned!  

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A last note: The shutdown started with a couple of heavy hailfalls, which resulted in hail clogging the water drains, immediately followed by heavy rains and water finding its way through the door seals on top of the enclosure, ending on the telescope. Damage was limited, but unfortunately, the oil used for the hydrostatic bearings on which the mount rides (both in azimuth and elevation) was contaminated by water. So, instead of moving right away to the usual shutdown activities, some of our staff had to take care of purging the whole oil system, cleaning up before replenishing it with fresh oil. Fortunately, we were able to clean the contaminated oil at base camp and to use it again.

Water on one of the mirrors after the hail storm. Not a welcome start for a shutdown, but at least the mirrors were going to be washed or realuminized!

The source of the flooding has been identified and corrective action will be taken as soon as possible.