23 research outputs found
Structure in the Disk of epsilon Aurigae: Analysis of the ARCES and TripleSpec data obtained during the 2010 eclipse
Context: Worldwide interest in the recent eclipse of epsilon Aurigae resulted
in the generation of several extensive data sets, including those related to
high resolution spectroscopic monitoring. This lead to the discovery, among
other things, of the existence of a mass transfer stream, seen notably during
third contact. Aims: We explored spectroscopic facets of the mass transfer
stream during third contact, using high resolution spectra obtained with the
ARCES and TripleSpec instruments at Apache Point Observatory. Methods: One
hundred and sixteen epochs of data between 2009 and 2012 were obtained, and
equivalent widths and line velocities measured, selected according to reports
of these being high versus low eccentricity disk lines. These datasets also
enable greater detail to be measured of the mid-eclipse enhancement of the He I
10830A line, and the discovery of the P Cygni shape of the Pa beta line at
third contact. Analysis: We found evidence of higher speed material, associated
with the mass transfer stream, persisting between third and fourth eclipse
contacts. We visualize the disk and stream interaction using SHAPE software,
and use CLOUDY software to estimate that the source of the enhanced He I 10830A
absorption arises from a region with log n = 10 (/cm3) and temperature of
20,000 K consistent with a mid B type central star. Results and Next Steps: Van
Rensbergen binary star evolutionary models are somewhat consistent with the
current binary parameters for the case of a 9 plus 8 solar mass initial binary,
evolving into a 2.3 and 14.11 solar mass end product after 35 Myr. Prior to the
next eclipse, it is possible to make predictions which suggest that continued
monitoring will help resolve standing questions about this binary
The galaxies missed by Hubble and ALMA: the contribution of extremely red galaxies to the cosmic census at 3<z<8
Using deep JWST imaging from JADES, JEMS and SMILES, we characterize
optically-faint and extremely red galaxies at that were previously
missing from galaxy census estimates. The data indicate the existence of
abundant, dusty and post-starburst-like galaxies down to M, below
the sensitivity limit of Spitzer and ALMA. Modeling the NIRCam and HST
photometry of these red sources can result in extreme, high values for both
stellar mass and star formation rate (SFR); however, including 7 MIRI filters
out to 21m results in decreased mass (median 0.6 dex for
logM/M10), and SFR (median 10 for SFR100
M/yr). At , our sample includes a high fraction of little red
dots (LRDs; NIRCam-selected dust-reddened AGN candidates). We significantly
measure older stellar populations in the LRDs out to rest-frame 3m (the
stellar bump) and rule out a dominant contribution from hot dust emission, a
signature of AGN contamination to stellar population measurements. This allows
us to measure their contribution to the cosmic census at , below the
typical detection limits of ALMA (). We find that
these sources, which are overwhelmingly missed by HST and ALMA, could
effectively double the obscured fraction of the star formation rate density at
compared to some estimates, showing that prior to JWST, the obscured
contribution from fainter sources could be underestimated. Finally, we identify
five sources with evidence for Balmer breaks and high stellar masses at
. While spectroscopy is required to determine their nature, we
discuss possible measurement systematics to explore with future data.Comment: submitted to AAS Journals, comments welcome
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
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 (MaStar) 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 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). 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 (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys
Structure in the disc of epsilon Aurigae â analysis of ARCES and TripleSpec spectra from the 2010 eclipse
The Galaxies Missed by Hubble and ALMA: The Contribution of Extremely Red Galaxies to the Cosmic Census at 3 < z < 8
© 2024 The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Using deep JWST imaging from JADES, JEMS, and SMILES, we characterize optically faint and extremely red galaxies at z > 3 that were previously missing from galaxy census estimates. The data indicate the existence of abundant, dusty, and poststarburst-like galaxies down to 108 M â, below the sensitivity limit of Spitzer and the Atacama Large Millimeter/submillimeter Array (ALMA). Modeling the NIRCam and Hubble Space Telescope (HST) photometry of these red sources can result in extremely high values for both stellar mass and star formation rate (SFR); however, including seven MIRI filters out to 21 ÎŒm results in decreased masses (median 0.6 dex for log10(Mâ/Mâ) > 10) and SFRs (median 10Ă for SFR > 100 M â yrâ1). At z > 6, our sample includes a high fraction of âlittle red dotsâ (LRDs; NIRCam-selected dust-reddened active galactic nucleus (AGN) candidates). We significantly measure older stellar populations in the LRDs out to rest-frame 3 ÎŒm (the stellar bump) and rule out a dominant contribution from hot dust emission, a signature of AGN contamination to stellar population measurements. This allows us to measure their contribution to the cosmic census at z > 3, below the typical detection limits of ALMA (L IR < 1012 L â). We find that these sources, which are overwhelmingly missed by HST and ALMA, could effectively double the obscured fraction of the star formation rate density at 4 < z < 6 compared to some estimates, showing that prior to JWST, the obscured contribution from fainter sources could be underestimated. Finally, we identify five sources with evidence for Balmer breaks and high stellar masses at 5.5 < z < 7.7. While spectroscopy is required to determine their nature, we discuss possible measurement systematics to explore with future data.Peer reviewe
Recommended from our members
The Galaxies Missed by Hubble and ALMA: The Contribution of Extremely Red Galaxies to the Cosmic Census at 3 < z < 8
Abstract
Using deep JWST imaging from JADES, JEMS, and SMILES, we characterize optically faint and extremely red galaxies at z > 3 that were previously missing from galaxy census estimates. The data indicate the existence of abundant, dusty, and poststarburst-like galaxies down to 108
M
â, below the sensitivity limit of Spitzer and the Atacama Large Millimeter/submillimeter Array (ALMA). Modeling the NIRCam and Hubble Space Telescope (HST) photometry of these red sources can result in extremely high values for both stellar mass and star formation rate (SFR); however, including seven MIRI filters out to 21 ÎŒm results in decreased masses (median 0.6 dex for
log
10
(
M
â
/
M
â
)
> 10) and SFRs (median 10Ă for SFR > 100 M
â yrâ1). At z > 6, our sample includes a high fraction of âlittle red dotsâ (LRDs; NIRCam-selected dust-reddened active galactic nucleus (AGN) candidates). We significantly measure older stellar populations in the LRDs out to rest-frame 3 ÎŒm (the stellar bump) and rule out a dominant contribution from hot dust emission, a signature of AGN contamination to stellar population measurements. This allows us to measure their contribution to the cosmic census at z > 3, below the typical detection limits of ALMA (L
IR < 1012
L
â). We find that these sources, which are overwhelmingly missed by HST and ALMA, could effectively double the obscured fraction of the star formation rate density at 4 < z < 6 compared to some estimates, showing that prior to JWST, the obscured contribution from fainter sources could be underestimated. Finally, we identify five sources with evidence for Balmer breaks and high stellar masses at 5.5 < z < 7.7. While spectroscopy is required to determine their nature, we discuss possible measurement systematics to explore with future data.</jats:p