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We have used multiple mid-infrared observations at 4.5 m obtained with the infrared array camera, of the compact young stellar bipolar outflow Cep E to measure the proper motion of its brightest condensations. The images span a period of yr and have been reprocessed to achieve a higher angular resolution than their normal beam . We found that for a distance of 730 pc, the tangential velocities of the north and south outflow lobes are and respectively, and moving away from the central source roughly along the major axis of the flow. A simple 3D hydrodynamical simulation of the H2 gas in a precessing outflow supports this idea. Observations and models confirm that the molecular hydrogen gas, traced by the pure rotational transitions, moves at highly supersonic velocities without being dissociated. This suggests either a very efficient mechanism to reform H2 molecules along these shocks or the presence of some other mechanism (e.g. strong magnetic field) that shields the H2 gas.

MIPSGAL is a278 deg2 278     deg 2 survey of the inner Galactic plane using the Multiband Infrared Photometer forSpitzeraboard theSpitzer Space Telescope. The survey field was imaged in two passbands, 24 and 70 μm with resolutions of 6″ and 18″, respectively. The survey was designed to provide a uniform, well-calibrated and well-characterized data set for general inquiry of the inner Galactic plane and as a longer-wavelength complement to the shorter-wavelengthSpitzersurvey of the Galactic plane: Galactic Plane Infrared Mapping Survey Extraordinaire. The primary science drivers of the current survey are to identify all high-mass ( M > 5 M ⊙ M > 5     M ⊙ ) protostars in the inner Galactic disk and to probe the distribution, energetics, and properties of interstellar dust in the Galactic disk. The observations were planned to minimize data artifacts due to image latents at 24 μm and to provide full coverage at 70 μm. Observations at ecliptic latitudes within 15° of the ecliptic plane were taken at multiple epochs to help reject asteroids. The data for the survey were collected in three epochs, 2005 September–October, 2006 April, and 2006 October with all of the data available to the public. The estimated point-source sensitivities of the survey are 2 and 75 mJy (3 σ) at 24 and 70 μm, respectively. Additional data processing was needed to mitigate image artifacts due to bright sources at 24 μm and detector responsivity variations at 70 μm due to the large dynamic range of the Galactic plane. Enhanced data products including artifact-mitigated mosaics and point-source catalogs are being produced with the 24 μm mosaics already publicly available from the NASA/IPAC Infrared Science Archive. Some preliminary results using the enhanced data products are described.

We describe improvements to the data processing pipeline for theSpitzerMIPSGAL survey of the Galactic plane. These involve both improvements to the processing of the 24 μm data, in particular the handling of saturations and near-saturated data, and mitigation of various artifacts not corrected in the basic calibration pipeline. The artifacts addressed postpipeline are typically caused by passage across bright point sources very common in the Galactic plane, and include column-to-column “jailbar” striping, latency effects resulting in both short-duration afterimages and long-duration responsivity depressions, scattered light, and background-level mismatches. We describe the artifacts phenomenologically and present in detail the algorithms developed to correct them.

The line profiles of dense cores in infrared-dark clouds indicate the presence of young stellar objects (YSOs), but the youth of the YSOs and the large distances to the clouds make it difficult to distinguish the outflows that normally accompany star formation from turbulence within the cloud. We report here the first unambiguous identification of a bipolar outflow from a young stellar object (YSO) in an infrared-dark cloud, using observations of SiO to distinguish the relatively small amounts of gas in the outflow from the rest of the ambient cloud. Key words: infrared-dark clouds, star formation, bipolar outflows, SiO, G81.56+0.10.

We have used multiple mid-infrared observations at 4.5 micron obtained with the Infrared Array Camera, of the compact (~1.4 arcmin) young stellar bipolar outflow Cep E to measure the proper motion of its brightest condensations. The images span a period of ~6 yr and have been reprocessed to achieve a higher angular resolution (~0.8 arcsec) than their normal beam (2 arcsec). We found that for a distance of 730 pc, the tangential velocities of the North and South outflow lobes are 62+/-29 and 94+/-6 km/s respectively, and moving away from the central source roughly along the major axis of the flow. A simple 3D hydrodynamical simulation of the H2 gas in a precessing outflow supports this idea. Observations and model confirm that the molecular Hydrogen gas, traced by the pure rotational transitions, moves at highly supersonic velocities without being dissociated. This suggests either a very efficient mechanism to reform H2 molecules along these shocks or the presence of some other mechanism (e.g. strong magnetic field) that shields the H2 gas.

We have used the Spitzer Space Telescope in February 2016 to obtain high cadence, high signal-to-noise, 17-hour duration light curves of Neptune at 3.6 and 4.5 \\(\\mu\\)m. The light curve duration was chosen to correspond to the rotation period of Neptune. Both light curves are slowly varying with time, with full amplitudes of 1.1 mag at 3.6 \\(\\mu\\)m and 0.6 mag at 4.5 \\(\\mu\\)m. We have also extracted sparsely sampled 18-hour light curves of Neptune at W1 (3.4 \\(\\mu\\)m) and W2 (4.6 \\(\\mu\\)m) from the WISE/NEOWISE archive at six epochs in 2010-2015. These light curves all show similar shapes and amplitudes compared to the Spitzer light curves but with considerable variation from epoch to epoch. These amplitudes are much larger than those observed with Kepler/K2 in the visible (amplitude \\(\\sim\\)0.02 mag) or at 845 nm with the Hubble Space Telescope in 2015 and at 763 nm in 2016 (amplitude \\(\\sim\\) 0.2 mag). We interpret the Spitzer and WISE light curves as arising entirely from reflected solar photons, from higher levels in Neptune's atmosphere than for K2. Methane gas is the dominant opacity source in Neptune's atmosphere, and methane absorption bands are present in the HST 763, and 845 nm, WISE W1, and Spitzer 3.6 \\(\\mu\\)m filters.

We have monitored photometrically the Y0 brown dwarf WISEP J173835.52+273258.9 (W1738) at both near- and mid-infrared wavelengths. This ~1 Gyr-old 400K dwarf is at a distance of 8pc and has a mass around 5 M_Jupiter. We observed W1738 using two near-infrared filters at lambda~1um, Y and J, on Gemini observatory, and two mid-infrared filters at lambda~4um, [3.6] and [4.5], on the Spitzer observatory. Twenty-four hours were spent on the source by Spitzer on each of June 30 and October 30 2013 UT. Between these observations, around 5 hours were spent on the source by Gemini on each of July 17 and August 23 2013 UT. The mid-infrared light curves show significant evolution between the two observations separated by four months. We find that a double sinusoid can be fit to the [4.5] data, where one sinusoid has a period of 6.0 +/- 0.1 hours and the other a period of 3.0 +/- 0.1 hours. The near-infrared observations suggest variability with a ~3.0 hour period, although only at a <~2 sigma confidence level. We interpret our results as showing that the Y dwarf has a 6.0 +/- 0.1 hour rotation period, with one or more large-scale surface features being the source of variability. The peak-to-peak amplitude of the light curve at [4.5] is 3%. The amplitude of the near-infrared variability, if real, may be as high as 5 to 30%. Intriguingly, this size of variability and the wavelength dependence can be reproduced by atmospheric models that include patchy KCl and Na_2S clouds and associated small changes in surface temperature. The small number of large features, and the timescale for evolution of the features, is very similar to what is seen in the atmospheres of the solar system gas giants.

We examine the repeatability, reliability, and accuracy of differential exoplanet eclipse depth measurements made using the InfraRed Array Camera (IRAC) on the Spitzer Space Telescope during the post-cryogenic mission. We have re-analyzed an existing 4.5 {\\mu}m data set, consisting of 10 observations of the XO-3b system during secondary eclipse, using seven different techniques for removing correlated noise. We find that, on average, for a given technique, the eclipse depth estimate is repeatable from epoch to epoch to within 156 parts per million (ppm). Most techniques derive eclipse depths that do not vary by more than a factor 3 of the photon noise limit. All methods but one accurately assess their own errors: for these methods, the individual measurement uncertainties are comparable to the scatter in eclipse depths over the 10 epoch sample. To assess the accuracy of the techniques as well as to clarify the difference between instrumental and other sources of measurement error, we have also analyzed a simulated data set of 10 visits to XO-3b, for which the eclipse depth is known. We find that three of the methods (BLISS mapping, Pixel Level Decorrelation, and Independent Component Analysis) obtain results that are within three times the photon limit of the true eclipse depth. When averaged over the 10 epoch ensemble, 5 out of 7 techniques come within 60 ppm of the true value. Spitzer exoplanet data, if obtained following current best practices and reduced using methods such as those described here, can measure repeatable and accurate single eclipse depths, with close to photon-limited results.