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Institution

Smithsonian Astrophysical Observatory

FacilityCambridge, Massachusetts, United States
About: Smithsonian Astrophysical Observatory is a facility organization based out in Cambridge, Massachusetts, United States. It is known for research contribution in the topics: Galaxy & Stars. The organization has 1665 authors who have published 3622 publications receiving 132183 citations. The organization is also known as: SAO.
Topics: Galaxy, Stars, Telescope, Luminosity, White dwarf


Papers
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Journal ArticleDOI
TL;DR: The Atmospheric Imaging Assembly (AIA) as discussed by the authors provides multiple simultaneous high-resolution full-disk images of the corona and transition region up to 0.5 R ⊙ above the solar limb with 1.5-arcsec spatial resolution and 12-second temporal resolution.
Abstract: The Atmospheric Imaging Assembly (AIA) provides multiple simultaneous high-resolution full-disk images of the corona and transition region up to 0.5 R ⊙ above the solar limb with 1.5-arcsec spatial resolution and 12-second temporal resolution. The AIA consists of four telescopes that employ normal-incidence, multilayer-coated optics to provide narrow-band imaging of seven extreme ultraviolet (EUV) band passes centered on specific lines: Fe xviii (94 A), Fe viii, xxi (131 A), Fe ix (171 A), Fe xii, xxiv (193 A), Fe xiv (211 A), He ii (304 A), and Fe xvi (335 A). One telescope observes C iv (near 1600 A) and the nearby continuum (1700 A) and has a filter that observes in the visible to enable coalignment with images from other telescopes. The temperature diagnostics of the EUV emissions cover the range from 6×104 K to 2×107 K. The AIA was launched as a part of NASA’s Solar Dynamics Observatory (SDO) mission on 11 February 2010. AIA will advance our understanding of the mechanisms of solar variability and of how the Sun’s energy is stored and released into the heliosphere and geospace.

4,321 citations

Journal ArticleDOI
TL;DR: The Hinode satellite as discussed by the authors is the successor to the Yohkoh mission, which aims to understand how magnetic energy gets transferred from the photosphere to the upper atmosphere and results in explosive energy releases.
Abstract: The Hinode satellite (formerly Solar-B) of the Japan Aerospace Exploration Agency’s Institute of Space and Astronautical Science (ISAS/JAXA) was successfully launched in September 2006. As the successor to the Yohkoh mission, it aims to understand how magnetic energy gets transferred from the photosphere to the upper atmosphere and results in explosive energy releases. Hinode is an observatory style mission, with all the instruments being designed and built to work together to address the science aims. There are three instruments onboard: the Solar Optical Telescope (SOT), the EUV Imaging Spectrometer (EIS), and the X-Ray Telescope (XRT). This paper provides an overview of the mission, detailing the satellite, the scientific payload, and operations. It will conclude with discussions on how the international science community can participate in the analysis of the mission data.

1,904 citations

Journal ArticleDOI
TL;DR: In this paper, the authors report the results of the first sensitive L-band survey of the intermediate-age (2.5-30 Myr) clusters NGC 2264, NGC 2362, and NGC 1960.
Abstract: We report the results of the first sensitive L-band survey of the intermediate-age (2.5-30 Myr) clusters NGC 2264, NGC 2362, and NGC 1960. We use JHKL colors to obtain a census of the circumstellar disk fractions in each cluster. We find disk fractions of 52% ± 10%, 12% ± 4%, and 3% ± 3% for the three clusters, respectively. Together with our previously published JHKL investigations of the younger NGC 2024, Trapezium, and IC 348 clusters, we have completed the first systematic and homogeneous survey for circumstellar disks in a sample of young clusters that both span a significant range in age (0.3-30 Myr) and contain statistically significant numbers of stars whose masses span nearly the entire stellar mass spectrum. Analysis of the combined survey indicates that the cluster disk fraction is initially very high (≥80%) and rapidly decreases with increasing cluster age, such that one-half the stars within the clusters lose their disks in 3 Myr. Moreover, these observations yield an overall disk lifetime of ~6 Myr in the surveyed cluster sample. This is the timescale for essentially all the stars in a cluster to lose their disks. This should set a meaningful constraint for the planet-building timescale in stellar clusters. The implications of these results for current theories of planet formation are briefly discussed.

1,886 citations

Journal ArticleDOI
TL;DR: The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) as mentioned in this paper is dedicated to the fine spectroscopy (2.5 × 1.5 ) and fine imaging (angular resolution: 12 arcmin FWHM) of celestial gamma-ray sources in the energy range 15 −keV to 10 −MeV with concurrent source monitoring in the X −ray and optical (V −band, 550 −nm) energy ranges.
Abstract: The ESA observatory INTEGRAL (International Gamma-Ray Astrophysics Laboratory) is dedicated to the fine spectroscopy (2.5 keV FWHM @ 1 MeV) and fine imaging (angular resolution: 12 arcmin FWHM) of celestial gamma-ray sources in the energy range 15 keV to 10 MeV with concurrent source monitoring in the X-ray ( keV) and optical (V -band, 550 nm) energy ranges. INTEGRAL carries two main gamma-ray instruments, the spectrometer SPI (Vedrenne et al. [CITE]) – optimized for the high-resolution gamma-ray line spectroscopy (20 keV–8 MeV), and the imager IBIS (Ubertini et al. [CITE]) – optimized for high-angular resolution imaging (15 keV–10 MeV). Two monitors, JEM-X (Lund et al. [CITE]) in the () keV X-ray band, and OMC (Mas-Hesse et al. [CITE]) in optical Johnson V -band complement the payload. The ground segment includes the Mission Operations Centre at ESOC, ESA and NASA ground stations, the Science Operations Centre at ESTEC and the Science Data Centre near Geneva. INTEGRAL was launched on 17 October 2002. The observing programme is well underway and sky exposure (until June 2003) reaches ~1800 ks in the Galactic plane. The prospects are excellent for the scientific community to observe the high energy sky using state-of-the-art gamma-ray imaging and spectroscopy. This paper presents a high-level overview of INTEGRAL.

1,243 citations

Journal ArticleDOI
TL;DR: The Interface Region Imaging Spectrograph (IRIS) as mentioned in this paper provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 arcsec and up.
Abstract: The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 – 0.4 arcsec spatial resolution, two-second temporal resolution, and 1 km s−1 velocity resolution over a field-of-view of up to 175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332 – 1358 A, 1389 – 1407 A, and 2783 – 2834 A, including bright spectral lines formed in the chromosphere (Mg ii h 2803 A and Mg ii k 2796 A) and transition region (C ii 1334/1335 A and Si iv 1394/1403 A). Slit-jaw images in four different passbands (C ii 1330, Si iv 1400, Mg ii k 2796, and Mg ii wing 2830 A) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec × 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative–MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.

1,238 citations


Authors

Showing all 1666 results

NameH-indexPapersCitations
Lee Hartmann13457957649
David W. Latham12785267390
Chi Lin1251313102710
William R. Forman12080053717
Edo Berger11857847147
Joseph Silk108131758146
Jon M. Miller10770650126
Fabrizio Fiore10680443260
Randall V. Martin10539657917
Christopher F. McKee10336844919
John P. Hughes10161636396
Wallace L. W. Sargent9939730265
Bryan Gaensler9984439851
Alexey Vikhlinin9936735822
Matthew J. Holman9932046577
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20231
202154
2020100
201986
2018107
201787