Astronomical Journal最新文献

The Initial Mass Function of Low-mass Stars and Brown Dwarfs in the W3 Complex. W3 星群中低质量恒星和褐矮星的初始质量函数。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2021-03-01 Epub Date: 2021-02-22 DOI: 10.3847/1538-3881/abe044

M J Huston, K L Luhman

{"title":"The Initial Mass Function of Low-mass Stars and Brown Dwarfs in the W3 Complex.","authors":"M J Huston, K L Luhman","doi":"10.3847/1538-3881/abe044","DOIUrl":"10.3847/1538-3881/abe044","url":null,"abstract":"We have used archival infrared images obtained with the Wide Field Camera 3 on board the Hubble Space Telescope to constrain the initial mass function of low-mass stars and brown dwarfs in the W3 star-forming region. The images cover 438 arcmin2, which encompasses the entire complex, and were taken in the filters F110W, F139M, and F160W. We have estimated extinctions for individual sources in these data from their colors and have dereddened their photometry accordingly. By comparing an area of the images that contains the richest concentration of previously identified W3 members to an area that has few members and is dominated by background stars, we have estimated the luminosity function for members of W3 with masses of 0.03-0.4 M ⨀. That luminosity function closely resembles data in typical nearby star-forming regions that have much smaller stellar populations than W3 (≲500 vs. several thousand objects). Thus, we do not find evidence of significant variations in the initial mass function of low-mass stars and brown dwarfs with star-forming conditions, which is consistent with recent studies of other distant massive star-forming regions.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"161 3","pages":""},"PeriodicalIF":5.3,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8740690/pdf/nihms-1760863.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39799973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamical instabilities in systems of multiple short-period planets are likely driven by secular chaos: a case study of Kepler-102. 多个短周期行星系统的动力学不稳定性可能是由长期混沌驱动的:开普勒-102的一个案例研究。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2020-09-01 Epub Date: 2020-08-04 DOI: 10.3847/1538-3881/aba0b0

Kathryn Volk, Renu Malhotra

{"title":"Dynamical instabilities in systems of multiple short-period planets are likely driven by secular chaos: a case study of Kepler-102.","authors":"Kathryn Volk, Renu Malhotra","doi":"10.3847/1538-3881/aba0b0","DOIUrl":"https://doi.org/10.3847/1538-3881/aba0b0","url":null,"abstract":"We investigated the dynamical stability of high-multiplicity Kepler and K2 planetary systems. Our numerical simulations find instabilities in ~ 20% of the cases on a wide range of timescales (up to 5×109 orbits) and over an unexpectedly wide range of initial dynamical spacings. To identify the triggers of long-term instability in multi-planet systems, we investigated in detail the five-planet Kepler-102 system. Despite having several near-resonant period ratios, we find that mean motion resonances are unlikely to directly cause instability for plausible planet masses in this system. Instead, we find strong evidence that slow inward transfer of angular momentum deficit (AMD) via secular chaos excites the eccentricity of the innermost planet, Kepler-102 b, eventually leading to planet-planet collisions in ~ 80% of Kepler-102 simulations. Kepler-102 b likely needs a mass ≳ 0.1M ⊕, hence a bulk density exceeding about half Earth's, in order to avoid dynamical instability. To investigate the role of secular chaos in our wider set of simulations, we characterize each planetary system's AMD evolution with a \"spectral fraction\" calculated from the power spectrum of short integrations (~ 5 × 106 orbits). We find that small spectral fractions (≲ 0.01) are strongly associated with dynamical stability on long timescales (5 × 109 orbits) and that the median time to instability decreases with increasing spectral fraction. Our results support the hypothesis that secular chaos is the driver of instabilities in many non-resonant multi-planet systems, and also demonstrate that the spectral analysis method is an efficient numerical tool to diagnose long term (in)stability of multi-planet systems from short simulations.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"160 3","pages":""},"PeriodicalIF":5.3,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7709759/pdf/nihms-1645632.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38335102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

A Census of Star Formation in the Outer Galaxy. II. The GLIMPSE360 Field. 外银河系恒星形成普查。II.GLIMPSE360 星场。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2020-08-01 Epub Date: 2020-07-16 DOI: 10.3847/1538-3881/ab99c8

Elaine Winston, Joseph L Hora, Volker Tolls

{"title":"A Census of Star Formation in the Outer Galaxy. II. The GLIMPSE360 Field.","authors":"Elaine Winston, Joseph L Hora, Volker Tolls","doi":"10.3847/1538-3881/ab99c8","DOIUrl":"10.3847/1538-3881/ab99c8","url":null,"abstract":"We have conducted a study of star formation in the outer Galaxy from 65°< l < 265°in the region observed by the GLIMPSE360 program. This Spitzer warm mission program mapped the plane of the outer Milky Way with IRAC at 3.6 and 4.5 μm. We combine the IRAC, Wide-field Infrared Survey Explorer (WISE), and Two Micron All Sky Survey catalogs and our previous results from another outer Galaxy survey and identify a total of 47,338 young stellar objects (YSOs) across the field spanning >180° in Galactic longitude. Using the DBSCAN method on the combined catalog, we identify 618 clusters or aggregations of YSOs having five or more members. We identify 10,476 class I, 29,604 class II, and 7325 anemic class II/class III YSOs. The ratio of YSOs identified as members of clusters was 25,528/47,338, or 54%. We found that 100 of the clusters identified have previously measured distances in the WISE H II survey. We used these distances in our spectral energy distribution (SED) fitting of the YSOs in these clusters, of which 96 had YSOs with <3σ fits. We used the derived masses from the SED model fits to estimate the initial mass function (IMF) in the inner and outer Galaxy clusters; dividing the clusters by galactocentric distances, the slopes were Γ = 1.87 ± 0.31 above 3 M ⵙ for R Gal < 11.5 kpc and Γ = 1.15 ± 0.24 above 3 M ⵙ for R Gal > 11.5 kpc. The slope of the combined IMF was found to be Γ = 1.92 ± 0.42 above 3 M ⵙ. These values are consistent with each other within the uncertainties and with literature values in the inner Galaxy high-mass star formation regions. The slopes are likely also consistent with a universal Salpeter IMF.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"160 2","pages":""},"PeriodicalIF":5.3,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430174/pdf/nihms-1616200.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38300374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

NEW CANDIDATES FOR PLANETARY-MASS BROWN DWARFS IN IC 348. 新的候选行星质量褐矮星ICE 348.

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2020-08-01 Epub Date: 2020-07-09 DOI: 10.3847/1538-3881/ab96bb

K L Luhman, C J Hapich

引用次数: 0

REFINING THE CENSUS OF THE UPPER SCORPIUS ASSOCIATION WITH GAIA. 完善天蝎座上部与 Gaia 联系的普查。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2020-07-01 Epub Date: 2020-06-29 DOI: 10.3847/1538-3881/ab9599

K L Luhman, T L Esplin

{"title":"REFINING THE CENSUS OF THE UPPER SCORPIUS ASSOCIATION WITH GAIA.","authors":"K L Luhman, T L Esplin","doi":"10.3847/1538-3881/ab9599","DOIUrl":"10.3847/1538-3881/ab9599","url":null,"abstract":"We have refined the census of stars and brown dwarfs in the Upper Sco association (~ 10 Myr, ~145 pc) by 1) updating the selection of candidate members from our previous survey to include the high-precision astrometry from the second data release of Gaia, 2) obtaining spectra of a few hundred candidate members to measure their spectral types and verify their youth, and 3) assessing the membership (largely with Gaia astrometry) of 2020 stars toward Upper Sco that show evidence of youth in this work and previous studies. We arrive at a catalog of 1761 objects that are adopted as members of Upper Sco. The distribution of spectral types among the adopted members is similar to those in other nearby star-forming regions, indicating a similar initial mass function. In previous studies, we have compiled mid-infrared photometry from WISE and the Spitzer Space Telescope for members of Upper Sco and used those data to identify the stars that show evidence of circumstellar disks; we present the same analysis for our new catalog of members. As in earlier work, we find that the fraction of members with disks increases with lower stellar masses, ranging from ≲ 10% for > 1 M ⊙ to ~ 22% for 0.01-0.3 M ⊙. Finally, we have estimated the relative ages of Upper Sco and other young associations using their sequences of low-mass stars in <math> <mrow><msub><mi>M</mi> <mrow><msub><mi>G</mi> <mrow><mtext>RP</mtext></mrow> </msub> </mrow> </msub> </mrow> </math> versus G BP - G RP. This comparison indicates that Upper Sco is a factor of two younger than the β Pic association (21-24 Myr) according to both non-magnetic and magnetic evolutionary models.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"160 1","pages":""},"PeriodicalIF":5.3,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430175/pdf/nihms-1614017.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38281667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A SURVEY FOR NEW STARS AND BROWN DWARFS IN THE OPHIUCHUS STAR-FORMING COMPLEX. 对蛇夫座恒星形成复合体中的新星和褐矮星的探测。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2020-06-01 Epub Date: 2020-05-29 DOI: 10.3847/1538-3881/ab8dbd

T L Esplin, K L Luhman

{"title":"A SURVEY FOR NEW STARS AND BROWN DWARFS IN THE OPHIUCHUS STAR-FORMING COMPLEX.","authors":"T L Esplin, K L Luhman","doi":"10.3847/1538-3881/ab8dbd","DOIUrl":"10.3847/1538-3881/ab8dbd","url":null,"abstract":"We have performed a survey for new members of the Ophiuchus cloud complex using high-precision astrometry from the second data release of Gaia, proper motions measured with multi-epoch images from the Spitzer Space Telescope, and color-magnitude diagrams constructed with photometry from various sources. Through spectroscopy of candidates selected with those data, we have identified 155 new young stars. Based on available measurements of kinematics, we classify 102, 47, and six of those stars as members of Ophiuchus, Upper Sco, and other populations in Sco-Cen, respectively. We have also assessed the membership of all other stars in the vicinity of Ophiuchus that have spectroscopic evidence of youth from previous studies, arriving at a catalog of 373 adopted members of the cloud complex. For those adopted members, we have compiled mid-IR photometry from Spitzer and the Wide-field Infrared Survey Explorer and have used mid-IR colors to identify and classify circumstellar disks. We find that 210 of the members show evidence of disks, including 48 disks that are in advanced stages of evolution. Finally, we have estimated the relative median ages of the populations near the Ophiuchus clouds and the surrounding Upper Sco association using absolute K-band magnitudes (M K ) based on Gaia parallaxes. If we adopt an age 10 Myr for Upper Sco, then the relative values of M K imply median ages of ~ 2 Myr for L1689 and embedded stars in L1688, 3-4 Myr for low-extinction stars near L1688, and ~ 6 Myr for the group containing ρ Oph.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"159 6","pages":""},"PeriodicalIF":5.3,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405947/pdf/nihms-1614013.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38240972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Potential Themis Family Asteroid Contribution to the Jupiter-Family Comet Population. 忒弥斯家族小行星对木星家族彗星数量的潜在贡献。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2020-04-01 Epub Date: 2020-03-30 DOI: 10.3847/1538-3881/ab7899

Henry H Hsieh, Bojan Novaković, Kevin J Walsh, Norbert Schörghofer

{"title":"Potential Themis Family Asteroid Contribution to the Jupiter-Family Comet Population.","authors":"Henry H Hsieh, Bojan Novaković, Kevin J Walsh, Norbert Schörghofer","doi":"10.3847/1538-3881/ab7899","DOIUrl":"https://doi.org/10.3847/1538-3881/ab7899","url":null,"abstract":"Recent dynamical analyses suggest that some Jupiter family comets (JFCs) may originate in the main asteroid belt instead of the outer solar system. This possibility is particularly interesting given evidence that icy main-belt objects are known to be present in the Themis asteroid family. We report results from dynamical analyses specifically investigating the possibility that icy Themis family members could contribute to the observed population of JFCs. Numerical integrations show that such dynamical evolution is indeed possible via a combination of eccentricity excitation apparently driven by the nearby 2:1 mean-motion resonance with Jupiter, gravitational interactions with planets other than Jupiter, and the Yarkovsky effect. We estimate that, at any given time, there may be tens of objects from the Themis family on JFC-like orbits with the potential to mimic active JFCs from the outer solar system, although not all, or even any, may necessarily be observably active. We find that dynamically evolved Themis family objects on JFC-like orbits have semimajor axes between 3.15 au and 3.40 au for the vast majority of their time on such orbits, consistent with the strong role that the 2:1 mean-motion resonance with Jupiter likely plays in their dynamical evolution. We conclude that a contribution from the Themis family to the active JFC population is plausible, although further work is needed to better characterize this contribution.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"159 4","pages":""},"PeriodicalIF":5.3,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3847/1538-3881/ab7899","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37807390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Variability in the Massive Open Cluster NGC 1817 from K2: A Rich Population of Asteroseismic Red Clump, Eclipsing Binary, and Main-sequence Pulsating Stars. 来自K2的大质量疏散星团NGC 1817的变化:丰富的星震红团、食双星和主序脉动星。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2020-03-01 Epub Date: 2020-02-10 DOI: 10.3847/1538-3881/ab68df

Eric L Sandquist, Dennis Stello, Torben Arentoft, Karsten Brogaard, Frank Grundahl, Andrew Vanderburg, Anne Hedlund, Ryan DeWitt, Taylor R Ackerman, Miguel Aguilar, Andrew J Buckner, Christian Juarez, Arturo J Ortiz, David Richarte, Daniel I Rivera, Levi Schlapfer

{"title":"Variability in the Massive Open Cluster NGC 1817 from K2: A Rich Population of Asteroseismic Red Clump, Eclipsing Binary, and Main-sequence Pulsating Stars.","authors":"Eric L Sandquist, Dennis Stello, Torben Arentoft, Karsten Brogaard, Frank Grundahl, Andrew Vanderburg, Anne Hedlund, Ryan DeWitt, Taylor R Ackerman, Miguel Aguilar, Andrew J Buckner, Christian Juarez, Arturo J Ortiz, David Richarte, Daniel I Rivera, Levi Schlapfer","doi":"10.3847/1538-3881/ab68df","DOIUrl":"https://doi.org/10.3847/1538-3881/ab68df","url":null,"abstract":"We present a survey of variable stars detected in K2 Campaign 13 within the massive intermediate-age (~1 Gyr) open cluster NGC 1817. We identify a complete sample of 44 red clump stars in the cluster, and have measured asteroseismic quantities (ν max and/or Δν) for 29 of them. Five stars showed suppressed dipole modes, and the occurrence rates indicate that mode suppression is unaffected by evolution through core helium burning. A subset of the giants in NGC 1817 (and in the similarly aged cluster NGC 6811) have ν max and Δν values at or near the maximum observed for core helium-burning stars, indicating they have core masses near the minimum for fully nondegenerate helium ignition. Further asteroseismic study of these stars can constrain the minimum helium core mass in red clump stars and the physics that determines this limit. Two giant stars show photometric variations on timescales similar to previously measured spectroscopic orbits. Thirteen systems in the field show eclipses, but only five are probable cluster members. We identify 32 δ Sct pulsators, 27 γ Dor candidates, and 7 hybrids that are probable cluster members, with most being new detections. We used the ensemble properties of the δ Sct stars to identify stars with possible radial pulsation modes. Among the oddities we have uncovered are: an eccentric orbit for a short-period binary containing a δ Sct pulsating star; a rare subgiant within the Hertzsprung gap showing δ Sct pulsations; and two hot γ Dor pulsating star candidates.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"159 3","pages":""},"PeriodicalIF":5.3,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3847/1538-3881/ab68df","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37673872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

A SURVEY FOR NEW MEMBERS OF TAURUS FROM STELLAR TO PLANETARY MASSES. 从恒星质量到行星质量对金牛座新成员的调查。

IF 5.3 2区物理与天体物理

Astronomical Journal Pub Date : 2019-08-01 DOI: 10.3847/1538-3881/ab2594

T L Esplin, K L Luhman

{"title":"A SURVEY FOR NEW MEMBERS OF TAURUS FROM STELLAR TO PLANETARY MASSES.","authors":"T L Esplin, K L Luhman","doi":"10.3847/1538-3881/ab2594","DOIUrl":"https://doi.org/10.3847/1538-3881/ab2594","url":null,"abstract":"We present a large sample of new members of the Taurus star-forming region that extend from stellar to planetary masses. To identify candidate members at substellar masses, we have used color-magnitude diagrams and proper motions measured with several wide-field optical and infrared (IR) surveys. At stellar masses, we have considered the candidate members that were found in a recent analysis of high-precision astrometry from the Gaia mission. Using new and archival spectra, we have measured spectral types and assessed membership for these 161 candidates, 79 of which are classified as new members. Our updated census of Taurus now contains 519 known members. According to Gaia data, this census should be nearly complete for spectral types earlier than M6-M7 at A J < 1. For a large field encompassing ~ 72% of the known members, the census should be complete for K < 15.7 at A J < 1.5, which corresponds to ~ 5-13 M Jup for ages of 1-10 Myr based on theoretical evolutionary models. Our survey has doubled the number of known members at ≥M9 and has uncovered the faintest known member in M K , which should have a mass of ~3-10 ~ M Jup for ages of 1-10 Myr. We have used mid-IR photometry from the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer to determine whether the new members exhibit excess emission that would indicate the presence of circumstellar disks. The updated disk fraction for Taurus is ~0.7 at ≤M3.5 and ~0.4 at >M3.5.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"158 2","pages":""},"PeriodicalIF":5.3,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3847/1538-3881/ab2594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41221027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 39

OSSOS XV: PROBING THE DISTANT SOLAR SYSTEM WITH OBSERVED SCATTERING TNOS. ossosxv：用观测到的散射TNOS探测遥远的太阳系。

IF 5.1 2区物理与天体物理

Astronomical Journal Pub Date : 2019-07-01 Epub Date: 2019-07-02 DOI: 10.3847/1538-3881/ab2383

Nathan A Kaib, Rosemary Pike, Samantha Lawler, Maya Kovalik, Christopher Brown, Mike Alexandersen, Michele T Bannister, Brett J Gladman, Jean-Marc Petit

{"title":"OSSOS XV: PROBING THE DISTANT SOLAR SYSTEM WITH OBSERVED SCATTERING TNOS.","authors":"Nathan A Kaib, Rosemary Pike, Samantha Lawler, Maya Kovalik, Christopher Brown, Mike Alexandersen, Michele T Bannister, Brett J Gladman, Jean-Marc Petit","doi":"10.3847/1538-3881/ab2383","DOIUrl":"10.3847/1538-3881/ab2383","url":null,"abstract":"Most known trans-Neptunian objects (TNOs) gravitationally scattering off the giant planets have orbital inclinations consistent with an origin from the classical Kuiper belt, but a small fraction of these \"scattering TNOs\" have inclinations that are far too large (i > 45°) for this origin. These scattering outliers have previously been proposed to be interlopers from the Oort cloud or evidence of an undiscovered planet. Here we test these hypotheses using N-body simulations and the 69 centaurs and scattering TNOs detected in the Outer Solar Systems Origins Survey and its predecessors. We confirm that observed scattering objects cannot solely originate from the classical Kuiper belt, and we show that both the Oort cloud and a distant planet generate observable highly inclined scatterers. Although the number of highly inclined scatterers from the Oort Cloud is ~3 times less than observed, Oort cloud enrichment from the Sun's galactic migration or birth cluster could resolve this. Meanwhile, a distant, low-eccentricity 5 M⊕ planet replicates the observed fraction of highly inclined scatterers, but the overall inclination distribution is more excited than observed. Furthermore, the distant planet generates a longitudinal asymmetry among detached TNOs that is less extreme than often presumed, and its direction reverses across the perihelion range spanned by known TNOs. More complete models that explore the dynamical origins of the planet are necessary to further study these features. With observational biases well-characterized, our work shows that the orbital distribution of detected scattering bodies is a powerful constraint on the unobserved distant solar system.","PeriodicalId":55582,"journal":{"name":"Astronomical Journal","volume":"158 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6677154/pdf/nihms-1041952.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41221025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0