The SDSS-V focal plane fiber-positioning hardware and survey strategy were designed around the core science cases, whose target densities — and relative infrared vs optical needs — vary dramatically across the sky, from Baade’s window to high-latitudes. This inevitably leaves unallocated (or “open”) fibers.
In response to this SDSS-V opened a (series of) collaboration-internal “open fiber proposal” call. DR19 includes the 30 target category proposals that resulted from the first call in November 2020. Boundary conditions for these proposals were that:
- the science goals — complementing core science — could be reached with single 15~minute exposures using either the APOGEE (infrared) or BOSS (optical) spectrographs;
- the targeting information was freely available to all SDSS-V members, and a target selection function could be specified.
Much of the proposed science fell into three broad categories:
- more extensive surveying of AGNs and X-ray sources across the sky;
- broader stellar physics, in particular binary star physics, across the color-magnitude diagram (CMD);
- studying the Milky Way’s stellar halo and metal-poor population, which (intentionally) had not been a focus of the Galactic Genesis program.
These programs were reviewed by an consortium-internal independent panel in early 2021, and their target categories are listed in the table below, including the number of targets submitted to the program.
| Carton Name | Description | Instrument | Available Targets1 |
|---|---|---|---|
| openfibertargets_nov2020_3 | Selection of eclipsing binaries (EA and EB) identified with ASAS-SN | BOSS | 34689 |
| openfibertargets_nov2020_5 | Selection of extremely metal poor ([Fe/H]<-3) stellar candidates identified on the basis of SkyMapper photometry, following the selection criteria outlined by Da Costa et al. (2019) | BOSS | 39099 |
| openfibertargets_nov2020_6a | Selection of stars in galactic halo on the basis of photometry from SkyMapper Southern Survey → Blue horizontal branch stars using criteria from Wang et al. 2020 | BOSS | 50611 |
| openfibertargets_nov2020_6b | Selection of stars in galactic halo on the basis of photometry from SkyMapper Southern Survey → Metal poor RGB stars using criteria from Huang et al. 2019 | BOSS | 340436 |
| openfibertargets_nov2020_6c | Selection of stars in galactic halo on the basis of photometry from SkyMapper Southern Survey: Metal poor dwarf stars | BOSS | 890043 |
| openfibertargets_nov2020_8 | Selection of stars in nearby young moving groups within 3 kpc from Kounkel et al. 2020, limited to sourced with ages log t>7.5 [yr] | BOSS/APOGEE | 704638 |
| openfibertargets_nov2020_9 | Selection of F stars performed using infrared colors | BOSS/APOGEE | 1197354 |
| openfibertargets_nov2020_10 | Selection of chemically anomalous (Na-rich, Al-rich, K-rich, P-rich, Si-rich, N-rich, s-process-rich, and CN-strong) stars previously observed by APOGEE to obtain a second radial velocity (RV) epoch to monitor RV variability | BOSS/APOGEE | 917 |
| openfibertargets_nov2020_11 | Selection of quasars observed during SDSS-I and -II which had only a single epoch to changes in emission lines and absorption line troughs over timescales of years to decades | BOSS | 39684 |
| openfibertargets_nov2020_12 | Selection of spectroscopic binaries from Price-Whelan et al. 2020 and Kounkel et al. 2021 identified in APOGEE spectra to receive an additional RV epoch | BOSS/APOGEE | 33577 |
| openfibertargets_nov2020_14 | Selection of unresolved main sequence + white dwarf binaries based on their location on the Gaia Color Magnitude Diagram (CMD) | BOSS | 10798 |
| openfibertargets_nov2020_15 | Selection of members of open clusters from Cantat-Gaudin et al. 2019 | BOSS/APOGEE | 177185 |
| openfibertargets_nov2020_17 | Selection of pre-main sequence star candidates within 500 pc from Zari et al. 2018 | BOSS | 32891 |
| openfibertargets_nov2020_18 | Selection of hard X-ray emitting sources (primarily AGNs) from XMM-Newton and Swift serendipitous surveys | BOSS | 10012 |
| openfibertargets_nov2020_19a | Selection of targets that received 2-min cadence monitoring by TESS in its first two years → Sources loaded into the database based on Gaia DR2 IDs | BOSS/APOGEE | 224773 |
| openfibertargets_nov2020_19b | Selection of targets that received 2-min cadence monitoring by TESS in its first two years →Sources loaded into the database based on Legacy Survey DR8 IDs | BOSS/APOGEE | 1605 |
| openfibertargets_nov2020_19c | Selection of targets that received 2-min cadence monitoring by TESS in its first two years →Sources loaded into the database based on PanSTARRS IDs | BOSS/APOGEE | 1615 |
| openfibertargets_nov2020_22 | Selection of binaries undergoing ellipsoidal variability identified in TESS full frame images from Green et al. (2023) | APOGEE | 28408 |
| openfibertargets_nov2020_24 | Selection of K/M metal-rich dwarfs in the distance range of 250pc<D<500pc identified based on their location on the Gaia Color Magnitude Diagram (CMD) | BOSS | 1323442 |
| openfibertargets_nov2020_25 | Selection of high proper motion K/M halo metal-poor stars up to 1 kpc identified based on their location on the Gaia Color Magnitude Diagram (CMD) | BOSS/APOGEE | 293741 |
| openfibertargets_nov2020_26 | Selection of quasars monitored in SDSS-I and II as a part of ultraviolet Broad Absorption Line (BAL) Quasar Variability Survey (Gibson et al. 2009) to receive an additional epoch of observations to monitor wind evolution | BOSS | 2105 |
| openfibertargets_nov2020_27 | Selection of bright quasar candidates with quasar-like Gaia and unWISE photometry, supplemented with multi-epoch variability observed by DES, excluding regions of high confusion | BOSS | 814963 |
| openfibertargets_nov2020_28a | Selection of halo stars → RR Lyrae sources selected based on the position on the Gaia Color Magnitude Diagram (CMD) that demonstrate variability in Gaia passbands | BOSS | 73627 |
| openfibertargets_nov2020_28b | Selection of halo stars → K giants outside of Galactic plane (|b|>10 deg) selected based on a combination of Gaia and 2MASS colors | BOSS | 49900 |
| openfibertargets_nov2020_28c | Selection of halo stars → Blue Horizontal Branch stars selected based on Gaia and GALEX colors | BOSS | 51234 |
| openfibertargets_nov2020_29 | Selection of extra-tidal stars associated with globular clusters | BOSS/APOGEE | 107688 |
| openfibertargets_nov2020_30 | Selection of bright sources in JWST North Ecliptic Pole Time-Domain Field | BOSS | 237 |
| openfibertargets_nov2020_31 | Selection of sources spectra of which previously have been obtained with RAVE to enable cross-calibration | APOGEE | 62275 |
| openfibertargets_nov2020_32 | Selection of resolved main sequence + white dwarf binaries from El-Badry & Rix (2018) | BOSS/APOGEE | 34230 |
| openfibertargets_nov2020_33 | Selection of candidate AGN, QSOs, and Blazars identified based on their ZTF variability flagged by ALeRCE light curve classifier (Sanchez-Saez et al 2020) | BOSS | 22250 |
| openfibertargets_nov2020_34a | Selection of sources across Gaia CMD to provide equal representation of all areas of parameter space → Nonvariable stars | BOSS | 8701166 |
| openfibertargets_nov2020_34b | Selection of sources across Gaia CMD to provide equal representation of all areas of parameter space → Variable stars | BOSS | 643546 |
| openfibertargets_nov2020_35a | Selection of metal-poor halo stars → Best & Brightest sources following Schlaufman & Casey (2014) using 2MASS and WISE photometry, regression trained on known metal-poor stars | BOSS | 345721 |
| openfibertargets_nov2020_35b | Selection of metal-poor halo stars → Sources selected using Skymapper DR1 photometric metallicities from Casagrande et al. 2019, limited to [Fe/H]<-1.7 | BOSS | 52696 |
| openfibertargets_nov2020_35c | Selection of metal-poor halo stars → Sources selected using metallicities derived from SAGE Survey (Zheng et al. 2018), limited to [Fe/H]<-2 | BOSS | 7521 |
| openfibertargets_nov2020_46 | Selection of sources which had at least 2 epochs of observations with LAMOST to provide another radial velocity (RV) epoch | BOSS | 663835 |
| openfibertargets_nov2020_47a | Selection of sources in the Large and Small Magellanic Clouds (LMC and SMC) based on Gaia photometry and astrometry → RGB stars | BOSS | 278987 |
| openfibertargets_nov2020_47b |
Selection of sources in the Large and Small Magellanic Clouds (LMC and SMC) based on Gaia photometry and astrometry → AGB stars |
APOGEE | 27731 |
| openfibertargets_nov2020_47c | Selection of sources in the Large and Small Magellanic Clouds (LMC and SMC) based on Gaia photometry and astrometry → Massive stars to be observed with BOSS | BOSS | 1000 |
| openfibertargets_nov2020_47d | Selection of sources in the Large and Small Magellanic Clouds (LMC and SMC) based on Gaia photometry and astrometry → Massive stars to be observed with APOGEE | APOGEE | 1000 |
| openfibertargets_nov2020_47e | Selection of sources in the Large and Small Magellanic Clouds (LMC and SMC) based on Gaia photometry and astrometry → Symbiotic stars | APOGEE | 24 |
| openfibertargets_nov2020_1000 | Selection of members of globular clusters from Baumgardt et al. (2018) and Harris (1996) | BOSS/APOGEE | 102172 |
| openfibertargets_nov2020_1001a | Selection of wide binaries identified by El Badry & Rix (2018) → All sources | BOSS/APOGEE | 81303 |
| openfibertargets_nov2020_1001b | Selection of wide binaries identified by El Badry & Rix (2018) → Subset of higher probability sources | BOSS | 10545 |