The Infrared Telescope Facility (Irtf) Spectral Library: Cool Stars

Rayner, John; Cushing, Michael C.; Vacca, William D.

doi:10.1088/0067-0049/185/2/289

Cited by 709 publications

(1,029 citation statements)

References 140 publications

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“…Left: observed spectrum of S0-38, as well as the template spectrum (shifted to an RV of 0 km s −1 ; Rayner et al 2009) used for thecross-correlation showing the wavelength range over which this analysis is performed. Dotted vertical lines indicate the rest wavelengths of the CO bandhead absorption features seen bothin the template and in S0-38ʼs spectrum.…”

Section: Resultsmentioning

confidence: 99%

An Improved Distance and Mass Estimate for SGR A* From a Multistar Orbit Analysis

Boehle

Ghez

Schödel

et al. 2016

ApJ

347

413

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We present new, more precise measurements of the mass and distance of our Galaxy's central supermassive black hole, Sgr A * . These results stem from a new analysis that more than doubles the time baseline for astrometry of faint stars orbiting Sgr A * , combining 2decades of speckle imaging and adaptive optics data. Specifically, we improve our analysis of the speckle images by using information about a star's orbit from the deep adaptive optics data (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013) to inform the search for the star in the speckle years (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005). When this new analysis technique is combined with the first complete re-reduction of Keck Galactic Center speckle images using speckle holography, we are able to track the short-period star S0-38 (K-band magnitude=17, orbital period=19 yr) through the speckle years. We use the kinematic measurements from speckle holography and adaptive optics to estimate the orbits of S0-38 and S0-2 and thereby improve our constraints of the mass (M bh ) and distance (R o ) of Sgr A * : M bh = (4.02±0.16±0.04) ×10 6 M e and 7.86±0.14±0.04 kpc. The uncertainties in M bh and R o as determined by the combined orbital fit of S0-2 and S0-38 are improved by a factor of 2 and 2.5, respectively, compared to an orbital fit of S0-2 alone and a factor of ∼2.5 compared to previous results from stellar orbits. This analysis also limits the extended dark mass within 0.01 pc to less than 0.13×10 6 M e at 99.7% confidence, a factor of 3 lower compared to prior work.

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Section: Resultsmentioning

confidence: 99%

An Improved Distance and Mass Estimate for SGR A* From a Multistar Orbit Analysis

Boehle

Ghez

Schödel

et al. 2016

ApJ

347

413

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“…CLASH observations of MACS J1149.6+2223 were obtained at eight different To assess whether MACS1149-JD1 could be a cool Galactic star, we compare its colors to a sample of 75 stellar templates of L,M,T dwarfs compiled from a spectral atlas 45,46 and Y dwarfs from stellar model atmospheres 47 . For each star we compute its predicted flux in F814W, F105W, F110W, F125W, F140W, F160W, IRAC 3.6 µm and 4.5 µm bands and normalize the fluxes so they match the F160W measurement for MACS1149-JD1.…”

Section: Solar System and Galactic Interlopersmentioning

confidence: 99%

A magnified young galaxy from about 500 million years after the Big Bang

Zheng

Postman

Zitrin

et al. 2012

Nature

309

342

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The early Universe at redshift z∼6-11 marks the reionization of the intergalactic medium, following the formation of the first generation of stars. However, those young galaxies at a cosmic age of < ∼ 500 million years (Myr, at z > ∼ 10) remain largely unexplored as they are at or beyond the sensitivity limits of current large telescopes. Gravitational lensing by galaxy clusters enables the detection of high-redshift galaxies that are fainter than what otherwise could be found in the deepest images of the sky. We report the discovery of an object found in the multi-band observations of the cluster MACS1149+22 that has a high probability of being a gravitationally magnified object from the early universe. The object is firmly detected (12σ) in the two reddest bands of HST/WFC3, and not detected below 1.2 µm, matching the characteristics of z∼9 objects. We derive a robust photometric redshift of z = 9.6 ± 0.2, corresponding to a cosmic age of 490 ± 15 Myr (i.e., 3.6% of the age of the Universe).The large number of bands used to derive the redshift estimate make it one of the most accurate estimates ever obtained for such a distant object. The significant magnification by cluster lensing (a factor of ∼15) allows us to analyze the object's ultra-violet and optical luminosity in its rest-2 frame, thus enabling us to constrain on its stellar mass, star-formation rate and age. If the galaxy is indeed at such a large redshift, then its age is less than 200 Myr (at the 95% confidence level), implying a formation redshift of z f < ∼ 14. The object is the first z>9 candidate that is bright enough for detailed spectroscopic studies with JWST, demonstrating the unique potential of galaxy cluster fields for finding highly magnified, intrinsically faint galaxies at the highest redshifts.Observational cosmology has established that the age of the Universe is 13.7 billion years, and the reionization of the vast intergalactic medium (IGM) started around redshift z ∼ 11, 1 as the result of radiation from the first generation of stars. The task of probing the most distant Universe is progressively challenging: While more than 10 5 quasars have been found, only one is at z > 7; 2 while thousands of gamma-ray burst events have been recorded, only one 3 is confirmed at z=8.3; and while thousands of galaxy candidates have been found at z ∼ 6, only one has been reported at z ∼ 10, 4 which is based on a single-band detection. Galaxies at z ∼ 10 are expected to be at a magnitude of ∼ 29 (in the AB system, used hereafter) 4, 5 , near the detection limits of the deepest fields observed by Hubble Space Telescope (HST), and beyond the spectroscopic capability of even the next generation of large telescopes.In this Letter we report the discovery of a gravitationally lensed source whose most likely redshift is z ∼ 9.6. The source, hereafter called MACS1149-JD1, is selected from a near-infrared detection image at significance of 22σ. MACS1149-JD1 has a unique flux distribution characterized by a) no detection at Galaxy clusters are the largest r...

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“…Finally, the largest category of contaminants amongst our candidates are M giants and supergiants, often with Br-γ emission, as shown in figures 11 and 12 (cf. Rayner, Cushing, & Vacca 2009). Contaminants with no emission were generally chosen using criteria from the He ii and Br-γ filters early on in the selection process; due to the shape of the spectra, these stars appeared brighter in those filters than in at least one of the continuum filters.…”

Section: Resultsmentioning

confidence: 99%

A near-infrared survey of the inner Galactic plane for Wolf–Rayet stars – III. New methods: faintest WR stars

Kanarek

Shara

Faherty

et al. 2015

Mon. Not. R. Astron. Soc.

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A new method of image subtraction is applied to images from a J, K, and narrow-band imaging survey of 300 deg 2 of the plane of the Galaxy, searching for new Wolf-Rayet stars. Our survey spans 150 • in Galactic longitude and reaches b = ±1 • with respect to the Galactic plane. The survey has a useful limiting magnitude of K = 15 over most of the observed Galactic plane, and K = 14 (due to severe crowding) within a few degrees of the Galactic centre. The new image subtraction method described here (better than aperture or even point-spread-function photometry in very crowded fields) detected several thousand emission-line candidates. In 2011 and 2012 June and July, we spectroscopically followed up on 333 candidates with MDM-TIFKAM and IRTF-SPEX, discovering 89 emission-line sources. These include 49 Wolf-Rayet stars, 43 of them previously unidentified, including the most distant known Galactic WR stars, more than doubling the number on the far side of the Milky Way. We also demonstrate our survey's ability to detect very faint PNe and other NIR emission objects.

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The Infrared Telescope Facility (Irtf) Spectral Library: Cool Stars

Cited by 709 publications

References 140 publications

An Improved Distance and Mass Estimate for SGR A* From a Multistar Orbit Analysis

An Improved Distance and Mass Estimate for SGR A* From a Multistar Orbit Analysis

A magnified young galaxy from about 500 million years after the Big Bang

A near-infrared survey of the inner Galactic plane for Wolf–Rayet stars – III. New methods: faintest WR stars

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