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The Near Infrared Camera for the James Webb Space Telescope (JWST) is delivering the imagery that astronomers have hoped for ever since JWST was proposed back in the 1990s. In the Commissioning Period that extended from right after launch to early 2022 July, NIRCam has been subjected to a number of performance tests and operational checks. The camera is exceeding prelaunch expectations in virtually all areas, with very few surprises discovered in flight. NIRCam also delivered the imagery needed by the Wavefront Sensing Team for use in aligning the telescope mirror segments. [ABSTRACT FROM AUTHOR]

The aim of the Lunar Legacy Project is to map the distribution of water on the Moon's surface through the detection and characterization of the 6 μ m spectral band indicative of molecular water. Spectra were taken with the Faint Object infraRed Camera for the SOFIA Telescope instrument on the Stratospheric Observatory for Infrared Astronomy (SOFIA) between 2018 and 2022. This paper describes the processing steps necessary to reduce the raw data downloaded from the SOFIA archive to create flux-calibrated spectra. The reduction mostly requires the SOFIA Redux package which can be downloaded from the SOFIA website, and some steps in the process require scripts written by our team in Python. [ABSTRACT FROM AUTHOR]

We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M 33 (Triangulum). In this paper, we present the dust and gas mass-loss rates by the pulsating Asymptotic Giant Branch (AGB) stars and red supergiants (RSGs) across the stellar disc of M 33. [ABSTRACT FROM AUTHOR]

Voyager 3 is a concept mission that sends a space telescope to the interstellar medium in a reasonable amount of time. Voyager 3 would take a direct image of an exoplanet using the solar gravitational lensing at the distance of 550 astronomical unit (AU). The spacecraft would use its suite of scientific instruments to study the environment of the local solar system and interstellar medium and finalize its primary mission by imaging an exoplanet. Two potential architectures are proposed to meet this mission directive, using multiple gravitational assists and sizable electric propulsion burns to achieve the high escape speeds necessary to reach 550 AU. This paper expands on the science mission objectives, trajectory, and the preliminary design of the baseline spacecraft. [ABSTRACT FROM AUTHOR]

We report on results of an observing campaign to support the Juno mission. At the beginning of 2016, using TEXES (Texas Echelon cross-dispersed Echelle Spectrograph), mounted on the NASA Infrared Telescope Facility (IRTF), we obtained data cubes of Jupiter in the 1930–1943  cm − 1 spectral ranges (around 5 µm), which probe the atmosphere in the 1–4 bar region, with a spectral resolution of ≈ 0.15  cm − 1 and an angular resolution of ≈ 1.4”. This dataset is analysed by a code that combines a line-by-line radiative transfer model with a non-linear optimal estimation inversion method. The inversion retrieves the vertical abundance profiles of NH 3 — which is the main contributor at these wavelengths — with a maximum sensitivity at ≈ 1–3 bar, as well as the cloud transmittance. This retrieval is performed on more than one thousand pixels of our data cubes, producing maps of the disk, where all the major belts are visible. We present our retrieved NH 3 abundance maps which can be compared with the distribution observed by Juno’s MWR (Bolton et al., 2017; Li et al., 2017) in the 2 bar region and discuss their significance for the understanding of Jupiter’s atmospheric dynamics. We are able to show important latitudinal variations — such as in the North Equatorial Belt (NEB), where the NH 3 abundance is observed to drop down to 60 ppmv at 2 bar — as well as longitudinal variability. In the zones, we find the NH 3 abundance to increase with depth, from 100 ± 15 ppmv at 1 bar to 500 ± 30 ppmv at 3 bar. We also display the cloud transmittance–NH 3 abundance relationship, and find different behaviour for the NEB, the other belts and the zones. Using a simple cloud model (Lacis and Hansen, 1974; Ackerman and Marley, 2001), we are able to fit this relationship, at least in the NEB, including either NH 3 -ice or NH 4 SH particles with sizes between 10 and 100 µm. [ABSTRACT FROM AUTHOR]

The Chinese Large Optical/Infrared Telescope is currently undergoing design studies. A ground-layer adaptive-optics system (GLAO) has been proposed, with a 14 -arcmin field of view (FOV) and moderate adaptive-optics correction using a deformable secondary mirror, several laser guide stars (LGS) and wavefront sensors. Due to its large FOV and relatively complex structure, some important problems should be analysed to aid budget considerations for the whole telescope. In this paper, we propose a FOV-related evaluation factor to describe the GLAO performance and use an end-to-end Monte Carlo simulation to test its performance under different configurations. To accelerate the parameter space exploration speed, we split the parameter space of the GLAO system and apply a bottom-up search procedure for parameter selection. We also propose a simplified turbulence geometric model to evaluate the GLAO performance with different turbulence-profile-related parameters. With the above methods, we analyse the required number of deformable mirror (DM) actuators, the number, position and magnitude of LGS and explore the DM tilt-conjugation problem for this GLAO system. [ABSTRACT FROM AUTHOR]

We present a retrieval analysis of TEXES (Texas Echelon Cross Echelle Spectrograph (Lacy et al., 2002)) spectra of Jupiter’s high latitudes obtained on NASA’s Infrared Telescope Facility on December 10 and 11th 2014. The vertical temperature profile and vertical profiles of C 2 H 2 , C 2 H 4 and C 2 H 6 were retrieved at both high-northern and high-southern latitudes and results were compared in ‘quiescent’ regions and regions known to be affected by Jupiter’s aurora in order to highlight how auroral processes modify the thermal structure and hydrocarbon chemistry of the stratosphere. In qualitative agreement with Sinclair et al. (2017a), we find temperatures in auroral regions to be elevated with respect to quiescent regions at two discrete pressures levels at approximately 1 mbar and 0.01 mbar. For example, in comparing retrieved temperatures at 70°N, 60°W (a representative quiescent region) and 70°N, 180°W (centred on the northern auroral oval), temperatures increase by 19.0  ±  4.2 K at 0.98 mbar, 20.8  ±  3.9 K at 0.01 mbar but only by 8.3  ±  4.9 K at the intermediate level of 0.1 mbar. We conclude that elevated temperatures at 0.01 mbar result from heating by joule resistance of the atmosphere and the energy imparted by electron and ion precipitation. However, temperatures at 1 mbar are considered to result either from heating by shortwave radiation of aurorally-produced haze particulates or precipitation of higher energy population of charged particles. Our former conclusion would be consistent with results of auroral-chemistry models, that predict the highest number densities of aurorally-produced haze particles at this pressure level ( Wong et al., 2000, 2003 ). C 2 H 2 and C 2 H 4 exhibit enrichments but C 2 H 6 remains constant within uncertainty when comparing retrieved concentrations in the northern auroral region with quiescent longitudes in the same latitude band. At 1 mbar, C 2 H 2 increases from 278.4  ±  40.3 ppbv at 70°N, 60°W to 564.4  ±  72.0 ppbv at 70°N, 180°W and at 0.01 mbar, over the same longitude range at 70°N, C 2 H 4 increases from 0.669  ±  0.129 ppmv to 6.509  ±  0.811 ppmv. However, we note that non-LTE (local thermodynamic equilibrium) emission may affect the cores of the strongest C 2 H 2 and C 2 H 4 lines on the northern auroral region, which may be a possible source of error in our derived concentrations. We retrieved concentrations of C 2 H 6 at 1 mbar of 9.03  ±  0.98 ppmv at 70°N, 60°W and 7.66  ±  0.70 ppmv at 70°N, 180°W. Thus, C 2 H 6 ’s concentration appears constant (within uncertainty) as a function of longitude at 70°N. [ABSTRACT FROM AUTHOR]

The lack of a large-aperture optical/infrared telescope has seriously affected the development of astronomy in China. In 2016, the authors published their concept study and suggestions for a 12-m telescope optical system. This article presents the authors' further research and some new results. Considering that this telescope should be a general-purpose telescope for a wide range of scientific goals and could be used for frontier scientific research in the future, the authors studied and designed a variety of 12-m telescope optical systems for comparison and final decision-making. In general, we still adopt our previous configuration, but the Nasmyth and prime-focus corrector systems have been greatly improved. In this article, the adaptive optics is given special attention. Ground-layer adaptive optics (GLAO) is adopted. It has a 14-arcmin field of view. The secondary mirror is used as the adaptive optical deformable mirror. Obviously, not all the optical systems in this telescope configuration will be used or constructed at the same stage. Some will be for the future and some are meant for research rather than for construction. [ABSTRACT FROM AUTHOR]

We present thermal properties and an improved shape model for potentially hazardous asteroid (162421) 2000 ET70. In addition to the radar data from 2000 ET70’s apparition in 2012, our model incorporates optical lightcurves and infrared spectra that were not included in the analysis of Naidu et al. (2013, Icarus 226, 323–335). We confirm the general “clenched fist” appearance of the Naidu et al. model, but compared to their model, our best-fit model is about 10% longer along its long principal axis, nearly identical along the intermediate axis, and about 25% shorter along the short axis. We find the asteroid’s dimensions to be 2.9 km × 2.2 km × 1.5 km (with relative uncertainties of about 10%, 15%, and 25%, respectively). With the available data, 2000 ET70’s period and pole position are degenerate with each other. The radar and lightcurve data together constrain the pole direction to fall along an arc that is about twenty-three degrees long and eight degrees wide. Infrared spectra from the NASA InfraRed Telescope Facility (IRTF) provide an additional constraint on the pole. Thermophysical modeling, using our SHERMAN software, shows that only a subset of the pole directions, about twelve degrees of that arc, are compatible with the infrared data. Using all of the available data, we find that 2000 ET70 has a sidereal rotation period of 8.944 h (± 0.009 h) and a north pole direction of ecliptic coordinates ( 52 ∘ , − 60 ∘ ) ± 6 ∘ . The infrared data, acquired over several dates, require that the thermal properties (albedo, thermal inertia, surface roughness) must change across the asteroid’s surface. By incorporating the detailed shape model and spin state into our thermal modeling, the multiple ground-based observations at different viewing geometries have allowed us to constrain the levels of the variations in the surface properties of this asteroid. [ABSTRACT FROM AUTHOR]

The Hungaria asteroids remain as survivors of late giant planet migration that destabilized a now extinct inner portion of the primordial asteroid belt and left in its wake the current resonance structure of the Main Belt. In this scenario, the Hungaria region represents a “purgatory” for the closest, preserved samples of the asteroidal material from which the terrestrial planets accreted. Deciphering the surface composition of these unique samples may provide constraints on the nature of the primordial building blocks of the terrestrial planets. We have undertaken an observational campaign entitled the Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS) to record near-infrared (NIR) reflectance spectra in order to characterize their taxonomy, surface mineralogy, and potential meteorite analogs. The overall objective of HARTSS is to evaluate the compositional diversity of asteroids located throughout the Hungaria region. This region harbors a collisional family of Xe-type asteroids, which are situated among a background (i.e., non-family) of predominantly S-complex asteroids. In order to assess the compositional diversity of the Hungaria region, we have targeted background objects during Phase I of HARTSS. Collisional family members likely reflect the composition of one original homogeneous parent body, so we have largely avoided them in this phase. We have employed NIR instruments at two ground-based telescope facilities: the NASA Infrared Telescope Facility (IRTF), and the Telescopio Nazionale Galileo (TNG). Our data set includes the NIR spectra of 42 Hungaria asteroids (36 background; 6 family). We find that stony S-complex asteroids dominate the Hungaria background population (29/36 objects; ∼80%). C-complex asteroids are uncommon (2/42; ∼5%) within the Hungaria region. Background S-complex objects exhibit considerable spectral diversity as band parameter measurements of diagnostic absorption features near 1- and 2-µm indicate that several different S-subtypes are represented therein, which translates to a variety of surface compositions. We identify the Gaffey S-subtype (Gaffey et al. [1993]. Icarus 106, 573–602) and potential meteorite analogs for 24 of these S-complex background asteroids. Additionally, we estimate the olivine and orthopyroxene mineralogy for 18 of these objects using spectral band parameter analysis established from laboratory-based studies of ordinary chondrite meteorites. Nine of the asteroids have band parameters that are not consistent with ordinary chondrites. We compared these to the band parameters measured from laboratory VIS+NIR spectra of six primitive achondrite (acapulcoite-lodranite) meteorites. These comparisons suggest that two main meteorite groups are represented among the Hungaria background asteroids: unmelted, nebular l - (and possibly LL- ordinary chondrites), and partially-melted primitive achondrites of the acapulcoite-lodranite meteorite clan. Our results suggest a source region for L chondrite like material from within the Hungarias, with delivery to Earth via leakage from the inner boundary of the Hungaria region. H chondrite like mineralogies appear to be absent from the Hungaria background asteroids. We therefore conclude that the Hungaria region is not a source for H chondrite meteorites. Seven Hungaria background asteroids have spectral band parameters consistent with partially-melted primitive achondrites, but the probable source region of the acapulcoite-lodranite parent body remains inconclusive. If the proposed connection with the Hungaria family to fully-melted enstatite achondrite meteorites (i.e., aubrites) is accurate (Gaffey et al. [1992]. Icarus 100, 95–109; Kelley and Gaffey [2002]. Meteorit. Planet. Sci. 37, 1815–1827), then asteroids in the Hungaria region exhibit a full range of petrologic evolution: from nebular, unmelted ordinary chondrites, through partially-melted primitive achondrites, to fully-melted igneous aubrite meteorites. [ABSTRACT FROM AUTHOR]

Submillimetre galaxies (SMGs) are among the most luminous dusty galaxies in the Universe, but their true nature remains unclear; are SMGs the progenitors of the massive elliptical galaxies we see in the local Universe, or are they just a short-lived phase among more typical star-forming galaxies? To explore this problem further, we investigate the clustering of SMGs identified in the SCUBA-2 Cosmology Legacy Survey. We use a catalogue of submillimetre (850 µm) source identifications derived using a combination of radio counterparts and colour/infrared selection to analyse a sample of 610 SMG counterparts in the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Survey (UKIDSS) Ultra Deep Survey (UDS), making this the largest high-redshift sample of these galaxies to date. Using angular cross-correlation techniques, we estimate the halo masses for this large sample of SMGs and compare them with passive and star-forming galaxies selected in the same field. We find that SMGs, on average, occupy high-mass dark matter haloes (Mhalo > 1013 M⊙) at redshifts z > 2.5, consistent with being the progenitors of massive quiescent galaxies in present-day galaxy clusters. We also find evidence of downsizing, in which SMG activity shifts to lower mass haloes at lower redshifts. In terms of their clustering and halo masses, SMGs appear to be consistent with other star-forming galaxies at a given redshift. [ABSTRACT FROM AUTHOR]

We present our near-infrared (NIR) imaging observations of two neutron star low-mass X-ray binaries XMMU J174716.1-281048 and SAX J1806.5-2215 obtained using the PANIC instrument on the 6.5-metre Magellan telescope and the WIYN High-Resolution Infrared Camera instrument on the 3.5-metre WIYN telescope, respectively. Both sources are members of the class of faint to very faint X-ray binaries and undergo very long X-ray outburst, hence classified as 'quasi-persistent X-ray binaries'. While XMMU J174716.1-281048 was active for almost 12 yr between 2003 and 2015, SAXJ1806.5-2215 has been active for more than 5 yr now since 2011. From our observations, we identify two NIR stars consistent with the Chandra X-ray error circle of XMMU J174716.1-281048. The comparison of our observations with the United Kingdom Infrared Telescope (UKIRT) Galactic plane observations taken during the same outburst, colour-colour diagram analysis and spectral energy distribution suggest that both stars are probably a part of the field population and are likely high-mass stars. Hence possibly neither of the two stars is a true NIR counterpart. For the faint X-ray binary SAX J1806.5-2215 during its current outburst, we detected an NIR star in our K-band WIYN observations consistent with its Chandra error circle. The identified NIR star was not detected during the UKIRT observations taken during its quiescent state. The comparison of two observations suggests that there was an increase in flux by at least one magnitude of the detected star during our observations, and hence suggests the detection of the likely counterpart of SAX J1806.5-2215. [ABSTRACT FROM AUTHOR]

High signal-to-noise images of Jupiter were made at wavelengths between 13.2 and 22.8 µm in five separate observing runs between 1996 June and 1997 November at the NASA Infrared Telescope Facility. Maps of Jupiter’s upper-tropospheric temperatures at pressures of 100 and 400 mbar were made from these images. We use the relatively frequent, well sampled data sets to examine in detail the short-term evolution of the temperature structure. Our 2–6 month sampling periods demonstrate that the longitudinal temperature structures evolve significantly in these short periods and exhibit wave features. Using a three-dimensional general circulation model simulation of Jupiter’s upper atmosphere, we show that the thermal structures are consistent with convectively generated Rossby waves that propagate upward from the lower to the upper atmosphere. [ABSTRACT FROM AUTHOR]

We report on spectroscopic observations of Saturn’s stratosphere in July 2011 with the Texas Echelon Cross Echelle Spectrograph (TEXES) mounted on the NASA InfraRed Telescope Facility (IRTF). The observations, targeting several lines of the CH 4 ν 4 band and the H 2 S(1) quadrupolar line, were designed to determine how Saturn’s stratospheric thermal structure was disturbed by the 2010 Great White Spot. A study of Cassini Composite Infrared Spectrometer (CIRS) spectra had already shown the presence of a large stratospheric disturbance centered at a pressure of 2 hPa, nicknamed the beacon B0, and a tail of warm air at lower pressures (Fletcher et al. [2012] Icarus 221, 560–586). Our observations confirm that the beacon B0 vertical structure determined by CIRS, with a maximum temperature of 180 ± 1 K at 2 hPa, is overlain by a temperature decrease up to the 0.2-hPa pressure level. Our retrieved maximum temperature of 180 ± 1 K is colder than that derived by CIRS (200 ± 1 K), a difference that may be quantitatively explained by terrestrial atmospheric smearing. We propose a scenario for the formation of the beacon based on the saturation of gravity waves emitted by the GWS. Our observations also reveal that the tail is a planet-encircling disturbance in Saturn’s upper stratosphere, oscillating between 0.2 and 0.02 hPa, showing a distinct wavenumber-2 pattern. We propose that this pattern in the upper stratosphere is either the signature of thermal tides generated by the presence of the warm beacon in the mid-stratosphere, or the signature of Rossby wave activity. [ABSTRACT FROM AUTHOR]

We present the first measurement of the trigonometric parallax of water masers associated with a Mira star, FV Bootis (FV Boo) using VLBI Exploration of Radio Astrometry (VERA). Based on our multi-epoch VERA observations, we derived the parallax to be 0.97 ± 0.06mas, which corresponds to a distance of 1.03+0.07+0.06 kpc. The water masers around FV Boo were spatially distributed over an area of 41 au x 41 au, and their internal motions indicate the presence of an outflow. Using the Kagoshima University 1 m optical/infrared telescope, we determined the period to be 305.6 d and the mean apparent magnitude to be +2.91 mag in the K'-band. On the period-luminosity plane, the obtained period and K'-band magnitude puts FV Boo slightly below the sequence of Miras, possibly due to circumstellar reddening. Combining our photometric data with COBE and 2MASS datasets spanning over 20 years, we found in the near infrared that FV Boo was significantly fainter in 2005 compared with preceding and later phases. Its color, however, did not show a large variation through this change. We infer that the dimming could be caused by an eclipse due to a cloud in a binary system. [ABSTRACT FROM AUTHOR]

Arrays of tens of thousands of sensitive far-infrared detectors coupled to a cryogenic 4-6 m class orbital telescope are needed to trace the assembly of galaxies over cosmic time. The sensitivity of a 4 Kelvin telescope observing in the far-infrared (30-300 $$\upmu $$ m) would be limited by zodiacal light and Galactic interstellar dust emission, and require broadband detector noise equivalent powers (NEPs) in the range of 3 $$\times 10^{-19}$$ W/ $$\sqrt{\mathrm{Hz}}$$ . We are fabricating and testing 96 element arrays of lumped-element kinetic inductance detectors (LEKIDs) designed to reach NEPs near this level in a low-background laboratory environment. The LEKIDs are fabricated with aluminum: the low normal-state resistivity of Al permits the use of very thin wire-grid absorber lines (150 nm) for efficient absorption of radiation, while the small volumes enable high sensitivities because quasiparticle densities are high. Such narrow absorption lines present a fabrication challenge, but we deposit TiN atop the Al to increase the robustness of the detectors and achieve a 95 $$\%$$ yield. We present the design of these Al/TiN bilayer LEKIDs and preliminary sensitivity measurements at 350 $$\upmu $$ m optically loaded by cold blackbody radiation. [ABSTRACT FROM AUTHOR]

Ultra-low-noise transition edge sensors (TES) with noise equivalent power lower than 2 $$\times $$ 10 $$^{-19}$$ W/Hz $$^{1/2 }$$ have been fabricated by SRON, which meet the sensitivity requirements for the far-infrared SAFARI instrument on space infrared telescope for cosmology and astrophysics. Our TES detector is based on a titanium/gold (Ti/Au) thermistor on a silicon nitride (SiN) island. The island is thermally linked with SiN legs to a silicon support structure at the bath temperature. The SiN legs are very thin (250 nm), narrow (500 nm), and long (above 300 $${\upmu } $$ m); these dimensions are needed in leg-isolated bolometers to achieve the required level of sensitivity. In this paper, we describe the latest fabrication process for our TES bolometers with improved sensitivity. [ABSTRACT FROM AUTHOR]

We present the results of an investigation to determine the longitudinal (zonal) distributions and temporal evolution of ices on the surface of Triton. Between 2002 and 2014, we obtained 63 nights of near-infrared (0.67–2.55 μ m) spectra using the SpeX instrument at NASA’s Infrared Telescope Facility (IRTF). Triton has spectral features in this wavelength region from N 2 , CO, CH 4 , CO 2 , and H 2 O. Absorption features of ethane (C 2 H 6 ) and 13 CO are coincident at 2.405 μ m, a feature that we detect in our spectra. We calculated the integrated band area (or fractional band depth in the case of H 2 O) in each nightly average spectrum, constructed longitudinal distributions, and quantified temporal evolution for each of the chosen absorption bands. The volatile ices (N 2 , CO, CH 4 ) show significant variability over one Triton rotation and have well-constrained longitudes of peak absorption. The non-volatile ices (CO 2 , H 2 O) show poorly-constrained peak longitudes and little variability. The longitudinal distribution of the 2.405 μ m band shows little variability over one Triton rotation and is 97 ± 44 ° and 92 ± 44 ° out of phase with the 1.58 μ m and 2.35 μ m CO bands, respectively. This evidence indicates that the 2.405 μ m band is due to absorption from non-volatile ethane. CH 4 absorption increased over the period of the observations while absorption from all other ices showed no statistically significant change. We conclude from these results that the southern latitudes of Triton are currently dominated by non-volatile ices and as the sub-solar latitude migrates northwards, a larger quantity of volatile ice is coming into view. [ABSTRACT FROM AUTHOR]

On 21 April 2013, during a co-ordinated Saturn auroral observing campaign, the northern and southern poles of the planet were observed from the Earth using the NASA Infrared Telescope Facility (IRTF), Keck, and Hubble Space Telescope (HST) simultaneously with the Cassini infrared, visible, and ultraviolet remote sensing instruments. We present simultaneous multi-scale and multi-wavelength analysis of the morphology of auroral emissions at Saturn. The visible main auroral emission vary between ∼ 2 and 10 kR on timescales of minutes and across spatial scales of down to ∼ 14 km on the planet. The H 2 Far Ultraviolet (FUV) brightness varies by a factor of ∼ 10, from ∼ 4–40 kR, over timescales of 1 min and spatial scales of 720 km. H 3 + infrared emissions vary less than the H 2 emissions, from ∼ 5–10 μ W m −2 sr −1 , over similar spatial scales ( ∼ 300 km) and timescales of a few seconds to a few hours. The fine-scale temporal and spatial features seen in the main oval show that complex structures are present even during quiet solar wind conditions. Diffuse ultraviolet emissions southward of the southern midnight main oval that are not seen in the infrared, implying a steep temperature gradient of ∼ 50 K over 2–4 ° latitude equatorward of the main oval. Dynamics on scales of ∼ 100 km at the poles are revealed by lower spatial resolution observations, the morphologies of which are partly consistent with overlapping local-time fixed and co-rotating current systems. We also present the first direct comparison of simultaneous infrared, visible, and ultraviolet auroral emissions at Saturn. Finally, the main auroral emissions are found to be approximately co-located in the midnight sector, forming an arc with a width of ∼ 0.5–1 ° , at 72–74° southern latitude, moving slightly equatorward with increasing local-time. [ABSTRACT FROM AUTHOR]

Diffractive telescope is an updated imaging technology, it differs from conventional refractive and reflective imaging system, which is based on the principle of diffraction image. However, one of the great challenges of design this optical system is that the diffractive optical element focuses on different wavelengths of light at different points in space, thereby distorting the color characteristics of image. In this paper, we designs a long-wavelength infrared diffractive telescope imaging system with flat surface Fresnel lens and cancels the infrared optical system chromatic aberration by another flat surface Fresnel lens, achieving broadband light (from 8 μm to 12 μm) to a common focus. At last, the diffuse spot size and MTF function provide diffractive-limited performance. [ABSTRACT FROM AUTHOR]

SPICA is a mid and far-infrared space mission to be submitted as a candidate to ESA's fifth medium class mission call, due in early 2016. This will be a joint project between ESA and JAXA, with ESA taking the lead role. If selected, SPICA will launch in ~2029 and operate for a goal lifetime of 5 years. The spacecraft will house a 2.5m telescope actively cooled to 8K, providing unprecedented sensitivity at mid-far infrared wavelengths. The low background environment and wavelength coverage provided by SPICA will make it possible to conduct detailed spectroscopic surveys of sources in both the local and distant Universe, deep into the most obscured regions. Using these data the evolution of galaxies over a broad and continuous range of cosmic time can be studied, spanning the era of peak star forming activity. SPICA will also provide unique access to, among others, the deep-lying water-ice spectral features and HD lines within planet forming discs. SPICA will conduct an extensive survey of both planet forming discs and evolved planetary systems, with the aim of providing the missing link between planet formation models and the large number of extrasolar planetary systems now being discovered. [ABSTRACT FROM AUTHOR]

The Local Group starburst galaxy IC 10 is the closest example of a blue compact galaxy. Here, we use optical gi imaging from Canada-France-Hawaii Telescope/MegaCam and near infrared JHK imaging from United Kingdom Infrared Telescope/Wide Field Camera to conduct a comprehensive survey of the structure of IC 10. We examine the spatial distribution of its resolved young, intermediate and old stellar populations to large radius and low effective surface brightness levels. Akin to other dwarfs with multiple populations of different ages, stellar populations of decreasing average age are increasingly concentrated in this galaxy. We find that the young, starbursting population and the asymptotic giant branch population are both offset from the geometric centre of the older red giant branch (RGB) population by a few hundred parsecs, implying that the younger star formation occurred significantly away from the centre of the galaxy. The RGB population traces an extended structure that is typical of blue compact galaxies, with an effective radius of ~5.75 arcmin (~1.25 kpc). These measurements show that IC 10 is much more extended than has previously been realized, and this blue compact galaxy is one of the most extended dwarf galaxies in the Local Group. The outermost isophotes of this galaxy are very regular in shape and essentially circular in morphology. Based on this analysis, we do not find any evidence to suggest that IC 10 has undergone a recent, significant, interaction with an unknown companion. [ABSTRACT FROM AUTHOR]

We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720-790 cm-1. These lines belong to bands ν = 1-0, 2-1, 3-2, 4-3, and 5-4, and involve rotational levels with Jlow ≲ 90. About 30 per cent of these lines are unblended or weakly blended and can be partially or entirely fitted with a code developed to model the mid-IR emission of a spherically symmetric circumstellar envelope composed of expanding gas and dust. The observed lines trace the envelope at distances to the star ≲35R* (⋍0.7 arcsec). The fits are compatible with an expansion velocity of 1 + 2.5(r/R* - 1) km s-1 between 1 and 5R*, 11kms-1 between 5 and 20R*, and 14.5 kms-1 outwards. The derived abundance profile of 28Si32S with respect to H2 is 4.9 × 10-6 between the stellar photosphere and 5R*, decreasing linearly down to 1.6 × 10-6 at 20R* and to 1.3 × 10-6 at 50R*. 28Si32S seems to be rotationally under local thermodynamic equilibrium (LTE) in the region of the envelope probed with our observations and vibrationally out of LTE in most of it. There is a red-shifted emission excess in the 28Si32S lines of band ν = 1-0 that cannot be found in the lines of bands ν = 2-1, 3-2, 4-3, and 5-4. This excess could be explained by an enhancement of the vibrational temperature around 20R* behind the star. The derived isotopic ratios 28Si/29Si, and 32S/34S are 17 and 14, compatible with previous estimates. [ABSTRACT FROM AUTHOR]

We present predictions for number counts and redshift distributions of galaxies detectable in continuum and in emission lines with the Mid-infrared (MIR) Instrument (SMI) proposed for the Space Infrared Telescope for Cosmology and Astrophysics. We have considered 24 MIR fine-structure lines, four polycyclic aromatic hydrocarbon bands (at 6.2, 7.7, 8.6 and 11.3 μm) and two silicate bands (in emission and in absorption) at 9.7 and 18.0 μm. Six of these lines are primarily associated with active galactic nuclei (AGNs), the others with star formation. A survey with the SMI spectrometers of 1-h integration per field of view (FoV) over an area of 1 deg² will yield 5σ detections of ≃ 140 AGN lines and of ≃ 5.2 × 104 star-forming galaxies, ≃ 1.6 × 104 of which will be detected in at least two lines. The combination of a shallow (20.0 deg², 1.4 × 10-1 h integration per FoV) and a deep survey (6.9 × 10-3 deg², 635 h integration time), with the SMI camera, for a total of ∼1000 h, will accurately determine the MIR number counts of galaxies and of AGNs over five orders of magnitude in flux density, reaching values more than one order of magnitude fainter than the deepest Spitzer 24 μm surveys. This will allow us to determine the cosmic star formation rate (SFR) function down to SFRs more than 100 times fainter than reached by the Herschel Observatory. [ABSTRACT FROM AUTHOR]

We have completed our seasonal monitoring of hydrogen peroxide and water vapor on Mars using ground-based thermal imaging spectroscopy, by observing the planet in March 2014, when water vapor is maximum, and July 2014, when, according to photochemical models, hydrogen peroxide is expected to be maximum. Data have been obtained with the Texas Echelon Cross Echelle Spectrograph (TEXES) mounted at the 3 m-Infrared Telescope Facility (IRTF) at Maunakea Observatory. Maps of HDO and H2O2 have been obtained using line depth ratios of weak transitions of HDO and H2O2 divided by CO2. The retrieved maps of H2O2 are in good agreement with predictions including a chemical transport model, for both the March data (maximum water vapor) and the July data (maximum hydrogen peroxide). The retrieved maps of HDO are compared with simulations by Montmessin et al. (2005, J. Geophys. Res., 110, 03006) and H2O maps are inferred assuming a mean martian D/H ratio of 5 times the terrestrial value. For regions of maximum values of H2O and H2O2, we derive, for March 1 2014 (Ls = 96°), H2O2 = 20+/-7 ppbv, HDO = 450+/-75 ppbv (45+/-8 pr-nm), and for July 3, 2014 (Ls = 156°), H2O2 = 30+/-7 ppbv, HDO = 375+/-70 ppbv (22+/-3 pr-nm). In addition, the new observations are compared with LMD global climate model results and we favor simulations of H2O2 including heterogeneous reactions on water-ice clouds. [ABSTRACT FROM AUTHOR]

We obtained 2–4 μm spectra of six M-type asteroids using the SpeX spectrograph at NASA’s Infrared Telescope Facility. We find evidence for hydrated minerals on all six asteroids, including two that were previously thought to be dry. One of our targets, (216) Kleopatra, shows rotational variability in the depth of its 3-μm feature. We also studied three of these asteroids in the 0.8–2.4 μm range using the NICS instrument at the Telescopio Nazionale Galileo (TNG) in La Palma, Spain. The discovery of spectral signatures of hydrated minerals on so many M-types is difficult to reconcile with a highly thermally evolved composition. It has been suggested that the hydrated minerals could have been delivered to M-types via impacts with primitive objects, or that the M-types may actually have primitive compositions that are not represented in meteorite collections. Understanding the origin and type of hydration on these asteroids will help determine which of these interpretations is correct. [ABSTRACT FROM AUTHOR]

Imaging spectroscopy at high resolution, in the infrared range, is a powerful tool for monitoring the behavior of minor species in planetary atmospheres and their evolution with latitude and longitude, season or local hour. Using the TEXES imaging spectrometer at the Infrared Telescope Facility (IRTF), this method has been applied for detecting and monitoring hydrogen peroxide and water vapor (using its proxy HDO) on Mars, then for monitoring sulfur dioxide and water (again using HDO) above the H 2 SO 4 cloud deck ( z = 65 km on Venus). Observations of Mars have shown that its atmosphere and climate are well reproduced by the Global Climatic Models. In contrast, strong spatio-temporal variations of SO 2 , observed above the Venus clouds, are not understood by the models. As a support of the forthcoming Juno space mission, a similar program has started on Jupiter to monitor its dynamics through 3-D maps of ammonia and phosphine. [ABSTRACT FROM AUTHOR]

We present analysis of high spectral resolution NIR spectra of CO and H 2 O in Comet C/2009 P1 (Garradd) taken during its 2011–2012 apparition with the CSHELL instrument on NASA’s Infrared Telescope Facility (IRTF). We also present analysis of observations of atomic oxygen in Comet Garradd obtained with the ARCES echelle spectrometer mounted on the ARC 3.5-m telescope at Apache Point Observatory and the Tull Coude spectrograph on the Harlan J. Smith 2.7-m telescope at McDonald Observatory. The observations of atomic oxygen serve as a proxy for H 2 O and CO 2 . We confirm the high CO abundance in Comet Garradd and the asymmetry in the CO/H 2 O ratio with respect to perihelion reported by previous studies. From the oxygen observations, we infer that the CO 2 /H 2 O ratio decreased as the comet moved towards the Sun, which is expected based on current sublimation models. We also infer that the CO 2 /H 2 O ratio was higher pre-perihelion than post-perihelion. We observe evidence for the icy grain source of H 2 O reported by several studies pre-perihelion, and argue that this source is significantly less abundant post-perihelion. Since H 2 O, CO 2 , and CO are the primary ices in comets, they drive the activity. We use our measurements of these important volatiles in an attempt to explain the evolution of Garradd’s activity over the apparition. [ABSTRACT FROM AUTHOR]

We report on archival near-infrared and mid-infrared observations of seven persistent X-ray sources situated in the Galactic bulge, using data from the UK Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS), the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and the Wide-field Infrared Survey Explorer (WISE) all-sky survey. We were able to successfully identify or provide upper flux limits for the systems SAX J1747.0-2853, IGR J17464-2811, AX J1754.2-2754, IGR J17597-2201, IGR J18134-1636, IGR J18256-1035 and Ser X-1 and constrain the nature of these systems. In the case of IGR J17597-2201, we present arguments that the source accretes matter from the stellar wind rather than via Roche-lobe overflow of the secondary. We suggest that, at its X-ray luminosity of 1034 - 35?erg?s-1, we are probing the poorly known class of wind-fed low-mass X-ray binaries (LMXBs). [ABSTRACT FROM AUTHOR]

We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope, of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this fourth paper of the series, we present a search for variable red giant stars in an almost square degree region comprising most of the galaxy's disc, carried out with the WFCAM (Wide Field CAMera) instrument in the K band. These data, taken during the period 2005–2007, were complemented by J- and H-band images. Photometry was obtained for 403 734 stars in this region; of these, 4643 stars were found to be variable, most of which are asymptotic giant branch (AGB) stars. The variable stars are concentrated towards the centre of M33, more so than low-mass, less-evolved red giants. Our data were matched to optical catalogues of variable stars and carbon stars and to mid-infrared photometry from the Spitzer Space Telescope. Most dusty AGB stars had not been previously identified in optical variability surveys, and our survey is also more complete for these types of stars than the Spitzer survey. The photometric catalogue is made publicly available at the Centre de Données astronomiques de Strasbourg. [ABSTRACT FROM AUTHOR]

Pluto’s lower atmosphere has been observed to evolve since the first definitive occultation detection in 1988. Possibilities for explaining the lower atmospheric structure include a steep thermal gradient and/or extinction, the latter of which can be characterized as a dependence between occultation flux and wavelength. On 2011 June 23, a 14.43 UCAC magnitude star ( R = 13.64) was occulted by Pluto as observed from multiple sites. Observations made at NASA’s 3-m Infrared Telescope Facility (IRTF) on Mauna Kea, Hawai’i, showed a full occultation of the star by Charon followed by an atmospheric graze by Pluto. Data were taken simultaneously in visible-wavelength images and low-resolution, near-infrared spectra. This dataset is unique in that (i) the double occultation allows astrometric measurements for Pluto and Charon as well as accurate calibration of the Pluto light curve, and (ii) the wavelength-resolved data serve as a test for atmospheric extinction. The graze reached a minimum normalized flux level of roughly 0.35, serving primarily as a probe of Pluto’s upper atmosphere (which is typically defined to be above half-light level in occultation light curves). However, the light curve is well fit by atmospheric models with a power-law thermal gradient, a clear upper atmosphere, and haze in the lower atmosphere. We find a negative dependence between flux and wavelength in the deepest part of Pluto’s atmosphere probed by the graze and in a spike during emersion. A simple extinction model for spherical, μm-sized tholins matches the observed spectral trends. While the atmospheric fits cannot rule out a clear atmosphere having a steep thermal gradient at the bottom, the flux-wavelength dependence and the feasibility of our particle-scattering fits suggest that Pluto’s lower atmosphere contained haze in 2011. These results provide an important link in monitoring Pluto’s dynamic atmosphere. [ABSTRACT FROM AUTHOR]

The clear angular separation of Pluto and Charon from ground-based telescopes has been enabled by improved technology, particularly adaptive optics systems. Near-infrared spectral data have revealed Charon’s surface to be rich in crystalline water ice and ammonia hydrates. In this work, we search for spectral differences across Charon’s surface with new near-infrared spectral data taken in the K -band (2.0–2.4 μm) with SINFONI on the VLT and NIRI on Gemini North as well as with previously published spectral data. The strength of the absorption band of ammonia hydrate is dependent on the state of the ice, concentration in H 2 O, grain size, temperature and exposure to radiation. We find variability of the band center and band depth among spectra. This could indicate variability of the distribution of ammonia hydrate across Charon’s surface. If the spectral variation is due to physical properties of Charon, the New Horizons flyby could find the concentration of ammonia hydrate heterogeneously distributed across the surface. Comparison between this work and New Horizons results will test the limits of ground-based reconnaissance. [ABSTRACT FROM AUTHOR]

We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ~1.5-10µm over a maximum timescale of 10 yr. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the ≲1AU region of the disk. Through analysis of the Pa β and Br γ lines in our data we derive a mass accretion rate in 2013 May of Ṁ ≈ (1.5-2.7) x 10-9Mʘyr-1. We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 yr of observations. We find that shifting the outer edge (r ≈ 0.3AU) of the inner disk by 0.05AU toward the star (in simulation of accretion and/or sculpting by forming planets) successfully reproduces the shift in NIR flux. We establish that the ~40-70AU dark ring imaged in the NIR by Quanz et al. and Momose et al. and at 7 mm by Osorio et al. may be reproduced with a 30% scaled density profile throughout the region, strengthening the link to this structure being dynamically cleared by one or more planetary mass bodies. [ABSTRACT FROM AUTHOR]

Context. VISTA Variables in the Vía Láctea (VVV) is one of six ESO Public Surveys using the 4 meter Visible and Infrared Survey Telescope for Astronomy (VISTA). The VVV survey covers the Milky Way bulge and an adjacent section of the disk, and one of the principal objectives is to search for new star clusters within previously unreachable obscured parts of the Galaxy. Aims. The primary motivation behind this work is to discover and analyze obscured star clusters in the direction of the inner Galactic disk and bulge. Methods. Regions of the inner disk and bulge covered by the VVV survey were visually inspected using composite JHKS color images to select new cluster candidates on the basis of apparent overdensities. DR1, DR2, CASU, and point spread function photometry of 10 × 10 arcmin fields centered on each candidate cluster were used to construct color-magnitude and color-color diagrams. Follow-up spectroscopy of the brightest members of several cluster candidates was obtained in order to clarify their nature. Results. We report the discovery of 58 new infrared cluster candidates. Fundamental parameters such as age, distance, and metallicity were determined for 20 of the most populous clusters. [ABSTRACT FROM AUTHOR]

Spectroscopic follow-up is a pre-requisite for studies of the formation and early evolution of brown dwarfs. Here, we present Infrared Telescope Facility/SpeX near-infrared spectroscopy of 30 candidate members of the young Upper Scorpius association, selected from our previous survey work. All 24 high-confidence members are confirmed as young very low mass objects with spectral types from M5 to L1, 15–20 of them are likely brown dwarfs. This high yield confirms that brown dwarfs in Upper Scorpius can be identified from photometry and proper motions alone, with negligible contamination from field objects (<4 per cent). Out of the six candidates with lower confidence, five might still be young very low mass members of Upper Scorpius, according to our spectroscopy. We demonstrate that some very low mass class II objects exhibit radically different near-infrared (0.6–2.5 μm) spectra from class III objects, with strong excess emission increasing towards longer wavelengths and partially filled in features at wavelengths shorter than 1.25 μm. These characteristics can obscure the contribution of the photosphere within such spectra. Therefore, we caution that near-infrared derived spectral types for objects with discs may be unreliable. Furthermore, we show that the same characteristics can be seen to some extent in all class II and even a significant fraction of class III objects (∼40 per cent), indicating that some of them are still surrounded by traces of dust and gas. Based on our spectra, we select a sample of objects with spectral types of M5–L1, whose near-infrared emission represents the photosphere only. We recommend the use of these objects as spectroscopic templates for young brown dwarfs in the future. [ABSTRACT FROM AUTHOR]