TY - JOUR
T1 - The Atacama Cosmology Telescope
T2 - A Search for Planet 9
AU - Naess, Sigurd
AU - Aiola, Simone
AU - Battaglia, Nick
AU - Bond, Richard J.
AU - Calabrese, Erminia
AU - Choi, Steve K.
AU - Cothard, Nicholas F.
AU - Halpern, Mark
AU - Hill, J. Colin
AU - Koopman, Brian J.
AU - Devlin, Mark
AU - McMahon, Jeff
AU - Dicker, Simon
AU - Duivenvoorden, Adriaan J.
AU - Dunkley, Jo
AU - Fanfani, Valentina
AU - Ferraro, Simone
AU - Gallardo, Patricio A.
AU - Guan, Yilun
AU - Han, Dongwon
AU - Hasselfield, Matthew
AU - Hincks, Adam D.
AU - Huffenberger, Kevin
AU - Kosowsky, Arthur B.
AU - Louis, Thibaut
AU - Macinnis, Amanda
AU - Madhavacheril, Mathew S.
AU - Nati, Federico
AU - Niemack, Michael D.
AU - Page, Lyman
AU - Salatino, Maria
AU - Schaan, Emmanuel
AU - Orlowski-Scherer, John
AU - Schillaci, Alessandro
AU - Schmitt, Benjamin
AU - Sehgal, Neelima
AU - Sifón, Cristóbal
AU - Staggs, Suzanne
AU - Engelen, Alexander Van
AU - Wollack, Edward J.
N1 - Publisher Copyright:
© 2021. The American Astronomical Society. All rights reserved.
PY - 2021/12/20
Y1 - 2021/12/20
N2 - We use Atacama Cosmology Telescope (ACT) observations at 98 GHz (2015–2019), 150 GHz (2013–2019), and 229 GHz (2017–2019) to perform a blind shift-and-stack search for Planet 9. The search explores distances from 300 au to 2000 au and velocities up to 6.′3 per year, depending on the distance (r). For a 5 Earth-mass Planet 9 the detection limit varies from 325 au to 625 au, depending on the sky location. For a 10 Earth-mass planet the corresponding range is 425 au to 775 au. The predicted aphelion and most likely location of the planet corresponds to the shallower end of these ranges. The search covers the whole 18,000 square degrees of the ACT survey. No significant detections are found, which is used to place limits on the millimeter-wave flux density of Planet 9 over much of its orbit. Overall we eliminate roughly 17% and 9% of the parameter space for a 5 and 10 Earth-mass Planet 9, respectively. These bounds approach those of a recent INPOP19a ephemeris-based analysis, but do not exceed it. We also provide a list of the 10 strongest candidates from the search for possible follow-up. More generally, we exclude (at 95% confidence) the presence of an unknown solar system object within our survey area brighter than 4–12 mJy (depending on position) at 150 GHz with current distance 300 au < r < 600 au and heliocentric angular velocity , corresponding to low-to-moderate eccentricities. These limits worsen gradually beyond 600 au, reaching 5–15 mJy by 1500 au.
AB - We use Atacama Cosmology Telescope (ACT) observations at 98 GHz (2015–2019), 150 GHz (2013–2019), and 229 GHz (2017–2019) to perform a blind shift-and-stack search for Planet 9. The search explores distances from 300 au to 2000 au and velocities up to 6.′3 per year, depending on the distance (r). For a 5 Earth-mass Planet 9 the detection limit varies from 325 au to 625 au, depending on the sky location. For a 10 Earth-mass planet the corresponding range is 425 au to 775 au. The predicted aphelion and most likely location of the planet corresponds to the shallower end of these ranges. The search covers the whole 18,000 square degrees of the ACT survey. No significant detections are found, which is used to place limits on the millimeter-wave flux density of Planet 9 over much of its orbit. Overall we eliminate roughly 17% and 9% of the parameter space for a 5 and 10 Earth-mass Planet 9, respectively. These bounds approach those of a recent INPOP19a ephemeris-based analysis, but do not exceed it. We also provide a list of the 10 strongest candidates from the search for possible follow-up. More generally, we exclude (at 95% confidence) the presence of an unknown solar system object within our survey area brighter than 4–12 mJy (depending on position) at 150 GHz with current distance 300 au < r < 600 au and heliocentric angular velocity , corresponding to low-to-moderate eccentricities. These limits worsen gradually beyond 600 au, reaching 5–15 mJy by 1500 au.
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U2 - 10.3847/1538-4357/ac2307
DO - 10.3847/1538-4357/ac2307
M3 - Article
AN - SCOPUS:85123530045
SN - 0004-637X
VL - 923
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 224
ER -