The NASA Spitzer Space Telescope

Gehrz, R. D.; Roellig, Thomas L.; Werner, M. W.; Fazio, G. G.; Houck, J. R.; Low, F. J.; Rieke, G. H.; Soifer, B. T.; Levine, Deborah A.; Romana, Edward A.

doi:10.1063/1.2431313

Cited by 132 publications

(119 citation statements)

References 60 publications

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“…We find that usingβ as an additional constraint for the 4.5 μm observations does not significantly improve the accuracy of our results. This is not surprising since the IRAC 4.5 μm channel is closer to the Spitzer diffraction limit of 5.5 μm (Gehrz et al 2007). We also find thatβ does not vary with stellar centroid position in the 5.8 and 8.0 μm observations, which are longward of the Spitzer of the diffraction limit.…”

Section: Discussionmentioning

confidence: 95%

“…Both the 3.6 and 4.5 μm channels of the IRAC instrument are shortward of the Spitzer 5.5 μm diffraction limit (Gehrz et al 2007) and exhibit undersampled PRFs whose shape changes as the stellar centroid moves from the center to the edge of a pixel causing intrapixel sensitivity variations. The PRFs in the 5.8 and 8.0 μm channels of the IRAC instrument exhibit a more Gaussian-like shape that is better sampled by the detector resulting in only small intrapixel sensitivity variations.…”

Section: Discussionmentioning

confidence: 99%

“…For our 3.6 μm observations we find that the optimal value of √ 1/b is 0.75 with a = c = 1. This difference in the a and b parameters accounts for the asymmetric shape of the IRAC PSF in the 3.6 μm bandpass (Gehrz et al 2007). For our 4.5 μm observations we find that a = b = c = 1 is optimal although the results are similar if we assume c = 0.…”

Section: Appendix B Intrapixel Sensitivity Correctionmentioning

confidence: 99%

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ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

Lewis

Knutson

Showman

et al. 2013

ApJ

177

294

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We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 μm bands of the Spitzer Space Telescope. The 3.6 and 4.5 μm data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest continuous phase curve observations obtained to date and the first full-orbit observations of a planet with an eccentricity exceeding 0.2. We present an improved non-parametric method for removing the intrapixel sensitivity variations in Spitzer data at 3.6 and 4.5 μm that robustly maps position-dependent flux variations. We find that the peak in planetary flux occurs at 4.39 ± 0.28, 5.84 ± 0.39, and 4.68 ± 0.37 hr after periapse passage with corresponding maxima in the planet/star flux ratio of 0.1138% ± 0.0089%, 0.1162% ± 0.0080%, and 0.1888% ± 0.0072% in the 3.6, 4.5, and 8.0 μm bands, respectively. Our measured secondary eclipse depths of 0.0996% ± 0.0072%, 0.1031% ± 0.0061%, 0.071% +0.029% −0.013% , and 0.1392% ± 0.0095% in the 3.6, 4.5, 5.8, and 8.0 μm bands, respectively, indicate that the planet cools significantly from its peak temperature before we measure the dayside flux during secondary eclipse. We compare our measured secondary eclipse depths to the predictions from a one-dimensional radiative transfer model, which suggests the possible presence of a transient day side inversion in HAT-P-2b's atmosphere near periapse. We also derive improved estimates for the system parameters, including its mass, radius, and orbital ephemeris. Our simultaneous fit to the transit, secondary eclipse, and radial velocity data allows us to determine the eccentricity (e = 0.50910 ± 0.00048) and argument of periapse (ω = 188.• 09 ± 0.• 39) of HAT-P-2b's orbit with a greater precision than has been achieved for any other eccentric extrasolar planet. We also find evidence for a long-term linear trend in the radial velocity data. This trend suggests the presence of another substellar companion in the HAT-P-2 system, which could have caused HAT-P-2b to migrate inward to its present-day orbit via the Kozai mechanism.

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Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Appendix B Intrapixel Sensitivity Correctionmentioning

confidence: 99%

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ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

Lewis

Knutson

Showman

et al. 2013

ApJ

177

294

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“…The observations are performed in the 3.6 μm and 4.5 μm bands of the InfraRed Array Camera (IRAC, Fazio et al 2004) on board the warm Spitzer Space Telescope (Werner et al 2004;Gehrz et al 2007). …”

Section: Mid-infrared Observations With Spitzermentioning

confidence: 99%

RISING FROM THE ASHES: MID-INFRARED RE-BRIGHTENING OF THE IMPOSTOR SN 2010da IN NGC 300

Lau

Kasliwal

Bond

et al. 2016

ApJ

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We present multi-epoch mid-infrared (IR) photometry and the optical discovery observations of the "impostor" supernova (SN) 2010da in NGC300 using new and archival Spitzer Space Telescope images and ground-based observatories. The mid-infrared counterpart of SN2010da was detected as Spitzer Infrared Intensive Transient Survey (SPIRITS)14bme in the SPIRITS, an ongoing systematic search for IR transients. Before erupting on 2010 May 24, the SN2010da progenitor exhibited a constant mid-IR flux at 3.6 and only a slight ∼10% decrease at 4.5 μm between 2003 November and 2007 December. A sharp increase in the 3.6 μm flux followed by a rapid decrease measured ∼150 days before and ∼80 days after the initial outburst, respectively, reveal a mid-IR counterpart to the coincident optical and high luminosity X-ray outbursts. At late times, after the outburst (∼2000 days), the 3.6 and 4.5 μm emission increased to over a factor of twotimes the progenitor flux and is currently observed (as of 2016 Feb) to be fading, but still above the progenitor flux. We attribute the re-brightening mid-IR emission to continued dust production and increasing luminosity of the surviving system associated with SN2010da. We analyze the evolution of the dust temperature (T d ∼700-1000 K), mass (M d ∼0.5-3.8×10 −7 M e ), luminosity (L IR ∼1.3-3.5×10 4 L e ), and the equilibrium temperature radius (R eq ∼6.4-12.2 au) in order to resolve the nature of SN2010da. We address the leading interpretation of SN2010da as an eruption from a luminous blue variable high-mass X-ray binary (HMXB) system. We propose that SN2010da is instead a supergiant (sg)B[e]-HMXB based on similar luminosities and dust masses exhibited by two other known sgB[e]-HMXB systems. Additionally, the SN2010da progenitor occupies a similar region on a mid-IR color-magnitude diagram (CMD) with known sgB[e] stars in the Large Magellanic Cloud. The lower limit estimated for the orbital eccentricity of the sgB[e]-HMXB (e>0.82) from X-ray luminosity measurements is high compared to known sgHMXBs and supports the claim that SN2010da may be associated with a newly formed HMXB system.

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“…Recent near-infrared (NIR) and mid-infrared (MIR) surveys (e.g., 2MASS, Skrutskie et al (2006); DENIS, Epchtein et al (1994) and SAGE, Meixner et al (2006)) have revealed tens of thousands of AGB star candidates in Large Magellanic Cloud (LMC). The SAGE (Meixner et al 2006) survey has observed the LMC in the Spitzer Space Telescope (Spitzer; Gehrz et al 2007) Infrared Array Camera (IRAC; 3.6, 4.5, 5.8 and 8.0 μm) and Multiband Imaging Photometer for Spitzer (MIPS; 24, 70 and 160 μm) bands. Blum et al (2006) and Srinivasan et al (2009) (hereafter, Paper I) used SAGE photometry to identify about 7000 carbon-rich AGB star candidates in the LMC.…”

Section: Introductionmentioning

confidence: 99%

The mass-loss return from evolved stars to the Large Magellanic Cloud

Srinivasan

Sargent

Matsuura

et al. 2010

A&A

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We present a radiative transfer model for the circumstellar dust shell around a Large Magellanic Cloud (LMC) long-period variable (LPV) previously studied as part of the Optical Gravitational Lensing Experiment (OGLE) survey of the LMC. OGLE LMC LPV 28579 (SAGE J051306.40-690946.3) is a carbon-rich asymptotic giant branch (AGB) star for which we have Spitzer broadband photometry and spectra from the SAGE and SAGE-Spec programs along with broadband UBVIJHK s photometry. By modeling this source, we obtain a baseline set of dust properties to be used in the construction of a grid of models for carbon stars. We reproduce the spectral energy distribution of the source using a mixture of amorphous carbon and silicon carbide with 15% SiC by mass. The grain sizes are distributed according to the KMH model, with γ = 3.5, a min = 0.01 μm and a 0 = 1.0 μm. The best-fit model produces an optical depth of 0.28 for the dust shell at the peak of the SiC feature (11.3 μm), with an inner radius of about 1430 R or 4.4 times the stellar radius. The temperature at this inner radius is 1310 K. Assuming an expansion velocity of 10 km s −1 , we obtain a dust mass-loss rate of 2.5 × 10 −9 M yr −1 . We calculate a 15% variation in this mass-loss rate by testing the sensitivity of the fit to variation in the input parameters. We also present a simple model for the molecular gas in the extended atmosphere that could give rise to the 13.7 μm feature seen in the spectrum. We find that a combination of CO and C 2 H 2 gas at an excitation temperature of about 1000 K and column densities of 3 × 10 21 cm −2 and 10 19 cm −2 respectively are able to reproduce the observations. Given that the excitation temperature is close to the temperature of the dust at the inner radius, most of the molecular contribution probably arises from this region. The luminosity corresponding to the first epoch of SAGE observations is 6580 L . For an effective temperature of about 3000 K, this implies a stellar mass of 1.5−2 M and an age of 1−2.5 Gyr for OGLE LMC LPV 28579. We calculate a gas mass-loss rate of 5.0 × 10 −7 M yr −1 assuming a gas:dust ratio of 200. This number is comparable to the gas mass-loss rates estimated from the period, color and 8 μm flux of the source.

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The NASA Spitzer Space Telescope

Cited by 132 publications

References 60 publications

ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

RISING FROM THE ASHES: MID-INFRARED RE-BRIGHTENING OF THE IMPOSTOR SN 2010da IN NGC 300

The mass-loss return from evolved stars to the Large Magellanic Cloud

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