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We present a $z = 0.94$ quasar, SDSS J004846.45-004611.9, discovered in the SDSS-III BOSS survey. A visual analysis of this spectrum reveals highly broadened and blueshifted narrow emission lines, in particular [Ne~V]$\lambda3426$ and [O~III]$\lambda5007$, with outflow velocities of 4000 km s$^{-1}$, along with unusually large [Ne V]$\lambda3426$/[Ne III]$\lambda3869$ ratios. The gas shows higher ionization at higher outflow velocities, indicating a connection between the powerful outflow and the unusual strength of the high ionization lines. The SED and the $i - \text{W3}$ color of the source reveal that it is likely a "core" Extremely Red Quasar (core ERQ); a candidate population of young AGN that are violently "blowing out" gas and dust from their centers. The dominance of host galaxy light in its spectrum and its fortuitous position in the SDSS S82 region allows us to measure its star formation history and investigate for variability for the first time in an ERQ. Our analysis indicates that SDSS J004846.45-004611.9 underwent a short-lived starburst phase 400 Myr ago and was subsequently quenched, possibly indicating a time-lag between star formation quenching and the onset of AGN activity. We also find that the strong extinction can be uniquely attributed to the AGN and does not persist in the host galaxy, contradicting a scenario where the source has recently transitioned from being a dusty sub-mm galaxy. In our relatively shallow photometric data, the source does not appear to be variable at $0.24-2.4~\mu$m in the restframe, most likely due to the dominant contribution of host galaxy starlight at these wavelengths., Comment: 23 pages, 8 figures, accepted for publication in ApJ

The Rapid infrared IMAger Spectrometer (RIMAS) is designed to quickly follow-up near-infrared (NIR) transient events, gamma ray bursts in particular. One way RIMAS will accomplish this mission is with its echelle spectrograph (R≈4000) that contain the first ruled grisms to be used in cross-dispersed mode for NIR astronomy. These ZnSe grisms were recently fabricated at Lawrence Livermore National Lab. This paper discusses the testing and categorization of the echelle spectrographs containing these grisms by comparing the modeled spectra to experimental spectra. This testing resulted in verification of the echelle spectrograph's quality, resolution, and dispersion. Efforts to develop a data reduction pipeline and upgrade RIMAS's detectors are ongoing.

The Nancy Grace Roman Space Telescope (Roman) formerly known as the Wide-Field Infrared Survey Telescope will answer fundamental questions about the evolution of dark energy over time and expand the catalog of known exoplanets into new regions of parameter space. Using a Hubble-sized mirror and 18 newly developed HgCdTe 4K × 4K photodiode arrays (H4RG-10), the Roman Space Telescope will measure the positions and shapes of hundreds of millions of galaxies, the light curves of thousands of supernovae, and the microlensing signals of over a thousand exoplanets toward the bulge of the Galaxy. These measurements require unprecedented sensitivity and characterization of the Wide Field Instrument, particularly its detectors. The Roman project undertook an extensive detector development program to create focal plane arrays that meet these science requirements. These prototype detectors have been characterized and their performance demonstrated in a relevant space-like environment (thermal vacuum, vibration, acoustic, and radiation testing), advancing the H4RG-10’s technology readiness level (TRL) to TRL-6. We present the performance characteristics of these TRL-6 demonstration devices.

We describe the results of principal component analysis (PCA) of up-the-ramp sampled IR array data from the HST WFC3 IR, JWST NIRSpec, and prototype WFIRST WFI detectors. These systems use respectively Teledyne H1R, H2RG, and H4RG-10 near-IR detector arrays with a variety of IR array controllers. The PCA shows that the Legendre polynomials approximate the principal components of these systems (i.e. they roughly diagonalize the covariance matrix). In contrast to the monomial basis that is widely used for polynomial fitting and linearization today, the Legendre polynomials are an orthonormal basis. They provide a quantifiable, compact, and (nearly) linearly uncorrelated representation of the information content of the data. By fitting a few Legendre polynomials, nearly all of the meaningful information in representative WFC3 astronomical datacubes can be condensed from 15 up-the-ramp samples down to 6 compressible Legendre coefficients per pixel. The higher order coefficients contain time domain information that is lost when one projects up-the-ramp sampled datacubes onto 2-dimensional images by fitting a straight line, even if the data are linearized before fitting the line. Going forward, we believe that this time domain information is potentially important for disentangling the various non-linearities that can affect IR array observations, i.e. inherent pixel non-linearity, persistence, burn in, brighter-fatter effect, (potentially) non-linear inter-pixel capacitance (IPC), and perhaps others., Comment: 26 pages, 10 figures, accepted by Journal of Astronomical Telescopes, Instruments, and Systems (JATIS)

Future space and ground based missions in the near infrared are planning to or will utilize the next generation of Teledyne's HxRG detectors, the HgCdTe 4K x 4K array (H4RG). The science cases of such missions will require optimal stability and noise performance. To assess the detailed performance of the H4RG, we have developed a small single detector testbed in NASA Goddard's Astrophysics Division IR detector lab. The testbed operates a H4RG array inside a large dewar using a room temperature Leach controller. The dewar will include two integrating spheres with controlled apertures using NIR LEDs as light sources as well as a calibrated photodiode to precisely measure flux. We present preliminary results of a banded H4RG-10 array on the bench. In the near future, we plan to use the test bed to investigate the specific origins of electronic noise in the test bed, persistence, and other flux dependent nonlinearities.

The University of Wisconsin Madison is building a NIR spectrograph (RSS-NIR) for the Southern African Large Telescope. The detector system uses a H2RG HdCdTe 1.7 μm cutoff array. We performed tests to measure and characterize the persistence of the detector to inform strategies to mitigate this effect. These tests use up-the- ramp group samples to get finer time resolution of the release of persistence. We share these test results. We also present preliminary results of the dependence of persistence on detector temperature. We conclude with an outline and assessment of a persistence calibration scheme.

At the University of Wisconsin-Madison, we are building and testing the near-infrared (NIR) spectrograph for the Southern African Large Telescope—RSS-NIR. RSS-NIR will be an enclosed cooled integral field spectrograph. The RSS-NIR detector system uses a HAWAII-2RG (H2RG) HgCdTe detector from Teledyne controlled by the SIDECAR ASIC and an Inter-University Centre for Astronomy and Astrophysics (IUCCA) ISDEC card. We have successfully characterized and optimized the detector system and report on the optimization steps and performance of the system. We have reduced the CDS read noise to ∼20 e− for 200 kHz operation by optimizing ASIC settings. We show an additional factor of 3 reduction of read noise using Fowler sampling techniques and a factor of 2 reduction using up-the-ramp group sampling techniques. We also provide calculations to quantify the conditions for sky-limited observations using these sampling techniques.

The Robert Stobie Spectrograph Near Infrared Instrument (RSS-NIR), a prime focus facility instrument for the 11-meter Southern African Large Telescope (SALT), is well into its laboratory integration and testing phase. RSS-NIR will initially provide imaging and single or multi-object medium resolution spectroscopy in an 8 arcmin field of view at wavelengths of 0.9 - 1.7 μm. Future modes, including tunable Fabry-Perot spectral imaging and polarimetry, have been designed in and can be easily added later. RSS-NIR will mate to the existing visible wavelength RSS-VIS via a dichroic beamsplitter, allowing simultaneous operation of the two instruments in all modes. Multi-object spectroscopy covering a wavelength range of 0.32 - 1.7 μm on 10-meter class telescopes is a rare capability and once all the existing VIS modes are incorporated into the NIR, the combined RSS will provide observational modes that are completely unique. The VIS and NIR instruments share a common telescope focal plane, and slit mask for spectroscopic modes, and collimator optics that operate at ambient observatory temperature. Beyond the dichroic beamsplitter, RSS-NIR is enclosed in a pre-dewar box operating at -40 °C, and within that is a cryogenic dewar operating at 120 K housing the detector and final camera optics and filters. This semi-warm configuration with compartments at multiple operating temperatures poses a number of design and implementation challenges. In this paper we present overviews of the RSSNIR instrument design and solutions to design challenges, measured performance of optical components, detector system optimization results, and an update on the overall project status.

We report on the status of the detector system for the Robert Stobie Spectrograph Near Infrared Arm (RSS-NIR) for the Southern African Large Telescope (SALT). The detector is a HAWAII-2RG array with a 1.7 μm cutoff wavelength. The controller incorporates a Teledyne cryogenic SIDECAR ASIC board inside the dewar and an FPGA interface card, developed by the Inter-University Centre for Astronomy and Astrophysics (IUCAA), outside the dewar. Data acquisition software written by IUCAA runs under a Linux operating system and communicates to the detector system through USB to fiber optic converters for electrical isolation on the telescope. System characterization is performed at the University of Wisconsin RSS-NIR Lab in a liquid nitrogen cooled test dewar. The test dewar contains a thermal control system that emulates operation of the cryocooler used in the instrument dewar and maintains a stable detector operating temperature of 120 K. Light is provided to the detector with near infrared LEDs mounted inside the dewar. We present preliminary data on system noise and plans for further characterization tests.

We present results from an optical photometric and spectroscopic survey of the young stellar population in L1641, the low-density star-forming region of the Orion A cloud south of the Orion Nebula Cluster (ONC). Our goal is to determine whether L1641 has a large enough low-mass population to make the known lack of high-mass stars a statistically-significant demonstration of environmental dependence of the upper mass stellar initial mass function (IMF). Our spectroscopic sample consists of IR-excess objects selected from the Spitzer/IRAC survey and non-excess objects selected from optical photometry. We have spectral confirmation of 864 members, with another 98 probable members; of the confirmed members, 406 have infrared excesses and 458 do not. Assuming the same ratio of stars with and without IR excesses in the highly-extincted regions, L1641 may contain as many as ~1600 stars down to ~0.1 solar mass, comparable within a factor of two to the the ONC. Compared to the standard models of the IMF, L1641 is deficient in O and early B stars to a 3-4 sigma significance level, assuming that we know of all the massive stars in L1641. With a forthcoming survey of the intermediate-mass stars, we will be in a better position to make a direct comparison with the neighboring, dense ONC, which should yield a stronger test of the dependence of the high-mass end of the stellar initial mass function upon environment., Comment: 19 pages, 21 figures. Accepted by ApJ