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The Seventeenth Data Release of the Sloan Digital Sky Surveys : Complete Release of MaNGA, MaStar, and APOGEE-2 Data
- 2022
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Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics (IOP). - 0067-0049 .- 1538-4365. ; 259:2
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Tidskriftsartikel (refereegranskat)abstract
- This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.
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| 3. |
- Ozbek, E. A., et al.
(författare)
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Failure Rates and Complications After Multiple-Revision ACL Reconstruction: Comparison of the Over-the-Top and Transportal Drilling Techniques
- 2023
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Ingår i: Orthopaedic Journal of Sports Medicine (OJSM). - 2325-9671. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Background:Multiple-revision anterior cruciate ligament reconstruction (ACLR) presents several technical challenges, often due to residual hardware, tunnel widening, malposition, or staged surgeries. Purpose:To compare failure and complication rates between the over-the-top (OTT) and transportal drilling (TD) techniques in patients undergoing surgery for failed revision ACLR. Study Design:Cohort study; Level of evidence, 3. Methods:The medical records of patients with at least 2 revision ACLRs using either the OTT or TD technique were reviewed retrospectively. Data on patient demographics, graft characteristics, number of revisions, concomitant procedures, complications, and failures were collected. Between-group comparisons of continuous and categorical variables were conducted with the independent-samples t test and the Fisher exact or chi-square test, respectively. Results:A total of 101 patients undergoing multiple-revision ACLR with OTT (n = 37, 37%) and TD (n = 64, 63%) techniques were included for analysis. The mean follow-up time was 60 months (range, 12-196 months). There were no significant differences in age, sex, body mass index, laterality, or follow-up length between groups (P > .05). Allograft was the graft used most frequently (n = 64; 67.3%) with no significant differences between groups in graft diameter (P > .05). There were no statistically significant differences between groups regarding rate of concurrent medial and lateral meniscus, cartilage, or lateral extra-articular procedures (P > .05). There was also no significant66 between-group difference in complication rate (OTT: n = 2 [5.4%]; TD: n = 8 [13%]) or graft failure rate (OTT: n = 4 [11%]; TD: n = 14 [22%]) (P > .05 for both). Conclusion:The results of this study showed notably high failure and complication rates in challenging multiple-revision ACLR. Complication and failure rates were similar between techniques, demonstrating that the OTT technique is a valuable alternative that can be used in a revision ACLR, particularly as a single-stage approach when the single-stage TD technique is not possible.
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- Sprague, A. L., et al.
(författare)
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Mercury: First Spectra from 0.7 to 5.5 µm Support Low FeO and Feldspathic Composition
- 2004
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Ingår i: 35th Lunar and Planetary Science Conference. ; , s. 1630-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Spectral measurements of Mercury's surface show an absence of absorptions centered near 0.9 and 1.2 micrometers. At the Moon these absorption bands are ubiquitous at varying depths. We have obtained spectra from the Moon for comparison. The lunar results
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| 5. |
- Sprague, A. L., et al.
(författare)
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Mercury: Near Infrared Spectroscopy with SpeX
- 2003
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Ingår i: American Astronomical Society, DPS meeting #35, #23.07. ; , s. 2307-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We report long slit, spatially resolved, high resolving power spectroscopy of Mercury's surface for longitudes 260 - 320 degrees. Spectra extend from 0.8 - 5.0 micrometers. Spectral features indicative of common silicate materials are found. There are var
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| 6. |
- Sprague, A. L., et al.
(författare)
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Spectral emissivity measurements of Mercury's surface indicate Mg- and Ca-rich mineralogy, K-spar, Na-rich plagioclase, rutile, with possible perovskite, and garnet
- 2009
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Ingår i: Planetary and Space Science. - : Elsevier BV. - 0032-0633 .- 1873-5088. ; 57:3, s. 364-383
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Tidskriftsartikel (refereegranskat)abstract
- Mid-infrared 2-D spectroscopic measurements from 8.0 to 12.7 gm of Mercury were taken using Boston University's Mid-Infrared Spectrometer and Imager (MIRSI) mounted on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, 7-11 April 2006. Measurements reported here cover radar bright region C, a dark plains region west of Caloris Basin, and the interior of Caloris Basin. By use of spectral deconvolution with a large spectral library composed of many mineral compositions and grain size separates, we fitted, or "unmixed", the Mercury spectra. We find mineral suites composed of magnesium-rich orthopyroxene and olivine, Ca-, Mg-, Na-rich clinopyroxene, potassium feldspar, and Na-bearing plagioclase feldspar. Both Ca- and Mg-rich garnet (pyrope and grossular, respectively) are apparently present in small amounts. Opaque minerals are required for spectral matching, with rutile (TiO2) repeatedly providing the "best fit". However, in the case of the radar bright region C, perovskite also contributed to a very good fit. Caloris Basin infill is rich in both potassium feldspar and Na-rich plagioclase. There is little or no olivine in the Caloris interior smooth plains. Together with the high alkali content, this indicates that resurfacing magmas were low to intermediate in SiO2. Data suggest the dark plains exterior to Caloris are highly differentiated low-iron basaltic magmas resulting in material that might be classified as oligorclase basalts. (C) 2009 Elsevier Ltd. All rights reserved
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| 7. |
- Warell, Johan, et al.
(författare)
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Constraints on Mercury's surface composition from MESSENGER and ground-based spectroscopy
- 2010
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Ingår i: Icarus. - : Elsevier BV. - 0019-1035 .- 1090-2643. ; 209:1, s. 138-163
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Tidskriftsartikel (refereegranskat)abstract
- The composition and chemistry of Mercury's regolith has beets calculated from MESSENGER MASCS 0 3-1 3 mu m spectra from the first flyby, using an implementation of Hapke's radiative transfer-based photometric model for light scattering in semi-transparent porous media, and a linear spectral mixing algorithm We combine this investigation with linear spectral fitting results from mid-infrared spectra and compare derived oxide abundances with mercurian formation models and lunar samples Hapke modeling results indicate a regolith that is optically dominated by finely comminuted particles with average area weighted grain size near 20 pin Mercury shows lunar-style space weathering, with maturation-produced microphase iron present at similar to 0 065 wt% abundance, with only small variations between mature and immature sites, the amount of which is unable to explain Mercury's low brightness relative to the Moon The average modal mineralogies for the flyby 1 spectra derived from Hapke modeling are 35-70% Na-rich plagioclase or orthoclase, up to 30% Mg-rich clinopyroxene, <5% Mg-rich orthopyroxene, minute olivine, similar to 20-45% low-Fe, low-Ti agglutinitic glass, and <10% of one or more lunar-like opaque minerals Mercurian average oxide abundances derived from Hapke models and mid-infrared linear fitting include 40-50 wt% SiO2, 10-35 wt% Al2O3, 1-8 wt% FeO, and <25 wt% TiO2, the inferred rock type is basalt Lunar-like opaques or glasses with high Fe and/or Ti abundances cannot on their own, or in combination, explain Mercury's low brightness The linear mixing results indicate the presence of clinopyroxenes that contain up to 21 wt% MnO and the presence of a Mn-rich hedenbergite Mn in M1 crystalline lattice sites of hedenbergite suppresses the strong 1 and 2 mu m crystal field absorption bands and may thus act as a strong darkening agent on Mercury Also, one or more of thermally darkened silicates, Fe-poor opaques and matured glasses, or Mercury-unique Ostwald-ripened microphase iron nickel may lower the albedo A major part of the total microphase Iron present in Mercury's regolith is likely derived from FeO that is not intrinsic to the crust but has been subsequently delivered by exogenic sources.
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| 8. |
- Warell, J., et al.
(författare)
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Moon: First Spectra from 0.7 to 5.5 µm
- 2004
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Ingår i: 35th Lunar and Planetary Science Conference. ; , s. 1624-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We present spectra of the Moon in the 0.7 - 5.5 micrometer wavelength region, obtained with SpeX on the IRTF. Spectra of Mercury were also obtained with the same instrument configuration and telescope during the observing period. Mercury spectra are discu
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| 9. |
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| 10. |
- Cremonese, G., et al.
(författare)
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Techniques and methods in ground-based observation of Mercury
- 2010
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Ingår i: Planetary and Space Science. - : Elsevier BV. - 0032-0633 .- 1873-5088. ; 58:1-2, s. 61-78
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Tidskriftsartikel (refereegranskat)abstract
- Modern telescopes and equipments have permitted excellent ground-based observations of Mercury, despite its proximity to the Sun. This is one of the main reasons why it has been observed using different techniques from high-resolution spectroscopy to high-resolution imaging from visible to infrared up to radio wavelengths. Because there is no obscuration from a thick atmosphere, the surface and exosphere have been imaged and the surface studied by infrared spectroscopy. This manuscript describes the techniques used to obtain information and new data of Mercury giving an overview of advantages and difficulties, and describes important scientific discoveries made with specific telescopic instrumentation.
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