The Galactic Centre is of fundamental astrophysical interest, but existing near-infrared surveys fall short to cover it adequately. Here we introduce the GALACTICNUCLEUS survey, a JHKs imaging survey of the centre of the Milky Way with a 0.2" angular resolution. We present the observations of Field 1 of our survey, centred approximately on SgrA* with an approximate size of 7.95 ' x 3.43 '. We describe the observational set-up and data reduction pipeline and discuss the quality of the data. Finally, we present some preliminary analysis of the data. The data were acquired with the near-infrared camera HAWK-I at the ESO VLT. Short readout times in combination with the speckle holography algorithm allowed us to produce final images with a stable, Gaussian PSF of 0.2" FWHM. Astrometric calibration is achieved via the VVV survey and photometric calibration is based on the SIRIUS/IRSF survey. The quality of the data is assessed by comparison between observations of the same field with different detectors of HAWK-I and at different times. We reach 5 sigma detection limits of approximately J = 22, H = 21, and Ks = 20. The photometric uncertainties are less than 0.05 at J < 20, H < 17 and Ks < 16. We distinguish five stellar populations in the colour-magnitude diagrams; three of them appear to belong to foreground spiral arms, and the other two correspond to a high- and a low-extinction star groups at the Galactic Centre. We use our data to analyse the near-infrared extinction curve and conclude that it can be described very well by a power-law with an index of JHKs = 2.31 +- 0.03. We do not find any evidence that this index depends on the position along the line-of-sight, or on the absolute value of the extinction. We produce extinction maps that show the clumpiness of the ISM at the Galactic Centre. Finally, we estimate that the majority of the stars have solar or super-solar metallicity.

/pdf/galacticnucleus-a-high-angular-resolution-jhk-imaging-survey-4a7z4logye.pdf

GALACTICNUCLEUS: A high angular resolution JHK imaging survey of the Galactic Centre

We present an overview of the "KIFF" project, which provides ultra-deep K-s-band imaging of all six of the Hubble Frontier Fields clusters, Abell 2744, MACS-0416, Abell S1063, Abell 370, MACS-0717, and MACS-1149. All of these fields have recently been observed with large allocations of Directors' Discretionary Time with the Hubble and Spitzer telescopes, covering 0.4 < lambda < 1.6 mu m and 3.6-4.5 mu m, respectively. VLT/HAWK-I integrations of the first four fields reach 5 sigma limiting depths of K-s similar to 26.0 (AB, point sources) and have excellent image quality (FWHM similar to 0.'' 4). The MACS-0717 and MACS-1149 fields are observable from the northern hemisphere, and shorter Keck/MOSFIRE integrations on those fields reach limiting depths of K-s = 25.5 and 25.1, with a seeing FWHM of similar to 0 '' 4 and 0.'' 5. In all cases the K-s-band mosaics cover the primary cluster and parallel HST/ACS + WFC3 fields. The total area of the K-s-band coverage is 490. arcmin(2). The K-s-band at 2.2 mu m crucially fills the gap between the reddest HST filter (1.6 mu m similar to H band) and the IRAC 3.6 mu m passband. While reaching the full depths of the space-based imaging is not currently feasible from the ground, the deep K-s-band images provide important constraints on both the redshifts and the stellar population properties of galaxies extending well below the characteristic stellar mass across most of the age of the universe, down to and including the redshifts of the targeted galaxy clusters (z less than or similar to 0.5). Reduced, aligned mosaics of all six survey fields are provided.

ULTRA-DEEP K S-BAND IMAGING of the HUBBLE FRONTIER FIELDS

We present an overview of the "KIFF" project, which provides ultra-deep Ks-band imaging of all six of the Hubble Frontier Fields clusters Abell 2744, MACS-0416, Abell S1063, Abell 370, MACS-0717 and MACS-1149. All of these fields have recently been observed with large allocations of Directors' Discretionary Time with the HST and Spitzer telescopes covering 0.4 < lambda < 1.6 microns and 3.6--4.5 microns, respectively. VLT/HAWK-I integrations of the first four fields reach 5-sigma limiting depths of Ks~26.0 (AB, point sources) and have excellent image quality (FWHM ~ 0."4). Shorter Keck/MOSFIRE integrations of the MACS-0717 (MACS-1149) field better observable in the north reach limiting depths Ks=25.5 (25.1) with seeing FWHM ~0."4 (0."5). In all cases the Ks-band mosaics cover the primary cluster and parallel HST/ACS+WFC3 fields. The total area of the Ks-band coverage is 490 arcmin^2. The Ks-band at 2.2 microns crucially fills the gap between the reddest HST filter (1.6 micron ~ H-band) and the IRAC 3.6 micron passband. While reaching the full depths of the space-based imaging is not currently feasible from the ground, the deep Ks-band images provide important constraints on both the redshifts and the stellar population properties of galaxies extending well below the characteristic stellar mass across most of the age of the universe, down to, and including, the redshifts of the targeted galaxy clusters (z < 0.5).

Ultra-deep Ks-band Imaging of the Hubble Frontier Fields

The adaptive module of the 4-m SOAR telescope (SAM) has been tested on the sky by clos ing the loop onnatural stars. Then it was re-con¯gured for operation with low-altitude Rayl eigh laser guide star in early 2011.We describe the performance of the SAM LGS system and various improvements made during one year of on-skytests. With acceptably small LGS spots of 1.6 00 the AO loop is robust and achieves a resolution gain of almosttwo times in the I band, under suitable conditions. The best FWHM resolution so far is 0 :25 00 over the 3 0 ¯eldof the CCD imager.Keywords: Laser Guide Star, Adaptive Optics 1. INTRODUCTION The idea of seeing improvement in a wide ¯eld by partial correction of low-altitude turbulence was proposed byRigaut 4 in 2001 and rapidly gained popularity. Several Ground-Layer Adaptive Optics (GLAO) instruments arepresently under development (e.g. ARGOS 2 or GRAAL 3 ), while the GLAO mode at MMT is already used forscience. 1 GLAO systems for extremely large telescopes are being proposed. The 4.1-m Souther n AstrophysicalResearch Telescope (SOAR) is developing a GLAO system based on ultra-violet (UV ) Rayleigh laser guide star(LGS). The SOAR Adaptive Module (SAM) is a facility instrument.

http://www.ctio.noao.edu/~atokovin/papers/sam_2012.pdf

Performance of the SOAR adaptive module with UV Rayleigh guide star

The Adaptive Optics Facility project is completing the integration of its systems at ESO Headquarters in Garching. The main test bench ASSIST and the 2 nd Generation M2-Unit (hosting the Deformable Secondary Mirror) have been granted acceptance late 2012. The DSM has undergone a series of tests on ASSIST in 2013 which have validated its optical performance and launched the System Test Phase of the AOF. This has been followed by the performance evaluation of the GRAAL natural guide star mode on-axis and will continue in 2014 with its Ground Layer AO mode. The GALACSI module (for MUSE) Wide-Field-Mode (GLAO) and the more challenging Narrow-Field-Mode (LTAO) will then be tested. The AOF has also taken delivery of the second scientific thin shell mirror and the first 22 Watt Sodium laser Unit. We will report on the system tests status, the performances evaluated on the ASSIST bench and advancement of the 4Laser Guide Star Facility. We will also present the near future plans for commissioning on the telescope and some considerations on tools to ensure an efficient operation of the Facility in Paranal.

ESO adaptive optics facility progress and first laboratory test results

The ESO Adaptive Optics Facility (AOF) consists in an evolution of one of the ESO VLT unit telescopes to a laser
driven adaptive telescope with a deformable mirror in its optical train, in this case the secondary 1.1m mirror, and four
Laser Guide Stars (LGSs). This evolution implements many challenging technologies like the Deformable Secondary
Mirror (DSM) including a thin shell mirror (1.1 m diameter and 2mm thin), the high power Na lasers (20W), the low
Read-Out Noise (RON) WaveFront Sensor (WFS) camera (< 1e-) and SPARTA the new generation of Real Time
Computers (RTC) for adaptive control. It also faces many problematic similar to any Extremely Large Telescope (ELT)
and as such, will validate many technologies and solutions needed for the European ELT (E-ELT) 42m telescope. The
AOF will offer a very large (7 arcmin) Field Of View (FOV) GLAO correction in J, H and K bands (GRAAL+Hawk-I),
a visible integral field spectrograph with a 1 arcmin GLAO corrected FOV (GALACSI-MUSE WFM) and finally a
LTAO 7.5" FOV (GALACSI-MUSE NFM). Most systems of the AOF have completed final design and are in
manufacturing phase. Specific activities are linked to the modification of the 8m telescope in order to accommodate the
new DSM and the 4 LGS Units assembled on its Center-Piece. A one year test period in Europe is planned to test and
validate all modes and their performance followed by a commissioning phase in Paranal scheduled for 2014.

Manufacturing of the ESO adaptive optics facility

We describe the design and development status of GRAAL, the 
Ground-layer adaptive optics assisted by Laser, which
will deliver enhanced images to the Hawk-I instrument on the VLT. GRAAL is an adaptive optics module, part of AOF,
the Adaptive optics facility, using four Laser- and one natural 
guide-stars to measure the turbulence, and correcting for it
by deforming the adaptive secondary mirror of a Unit telescope in the Paranal observatory.
The outstanding feature of GRAAL is the extremely wide field of view correction, over 10 arcmin diameter, with an
image enhancement of about 20% in average in K band. When observing GRAAL will provide FWHM better than 0.3"
40% of the time. Besides the Adaptive optics facility deformable mirror and Laser guide stars, the system uses subelectron
L3-CCD and a real-time computing platform, SPARTA.
GRAAL completed early this year a final design phase shared internally and outsourced for its mechanical part by the
Spanish company NTE. It is now in manufacturing, with a first light in the laboratory planned in 2011.

/pdf/graal-a-seeing-enhancer-for-the-nir-wide-field-imager-hawk-i-5e5cnl3zpf.pdf

GRAAL: a seeing enhancer for the NIR wide-field imager Hawk-I

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Manufacturing of the ESO adaptive optics facility

GRAAL: a seeing enhancer for the NIR wide-field imager Hawk-I