The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU. (arXiv:1904.05358v1 [astro-ph.EP])

The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU. (arXiv:1904.05358v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Nielsen_E/0/1/0/all/0/1">Eric L. Nielsen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosa_R/0/1/0/all/0/1">Robert J. De Rosa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Macintosh_B/0/1/0/all/0/1">Bruce Macintosh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_J/0/1/0/all/0/1">Jason J. Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ruffio_J/0/1/0/all/0/1">Jean-Baptiste Ruffio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chiang_E/0/1/0/all/0/1">Eugene Chiang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marley_M/0/1/0/all/0/1">Mark S. Marley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Saumon_D/0/1/0/all/0/1">Didier Saumon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Savransky_D/0/1/0/all/0/1">Dmitry Savransky</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ammons_S/0/1/0/all/0/1">S. Mark Ammons</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bailey_V/0/1/0/all/0/1">Vanessa P. Bailey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barman_T/0/1/0/all/0/1">Travis Barman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Blain_C/0/1/0/all/0/1">Celia Blain</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bulger_J/0/1/0/all/0/1">Joanna Bulger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chilcote_J/0/1/0/all/0/1">Jeffrey Chilcote</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cotten_T/0/1/0/all/0/1">Tara Cotten</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Czekala_I/0/1/0/all/0/1">Ian Czekala</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Doyon_R/0/1/0/all/0/1">Rene Doyon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Duchene_G/0/1/0/all/0/1">Gaspard Duchene</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Esposito_T/0/1/0/all/0/1">Thomas M. Esposito</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fabrycky_D/0/1/0/all/0/1">Daniel Fabrycky</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fitzgerald_M/0/1/0/all/0/1">Michael P. Fitzgerald</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Follette_K/0/1/0/all/0/1">Katherine B. Follette</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fortney_J/0/1/0/all/0/1">Jonathan J. Fortney</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gerard_B/0/1/0/all/0/1">Benjamin L. Gerard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Goodsell_S/0/1/0/all/0/1">Stephen J. Goodsell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Graham_J/0/1/0/all/0/1">James R. Graham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Greenbaum_A/0/1/0/all/0/1">Alexandra Z. Greenbaum</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hibon_P/0/1/0/all/0/1">Pascale Hibon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hinkley_S/0/1/0/all/0/1">Sasha Hinkley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hirsch_L/0/1/0/all/0/1">Lea A. Hirsch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hom_J/0/1/0/all/0/1">Justin Hom</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hung_L/0/1/0/all/0/1">Li-Wei Hung</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dawson_R/0/1/0/all/0/1">Rebekah Ilene Dawson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ingraham_P/0/1/0/all/0/1">Patrick Ingraham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kalas_P/0/1/0/all/0/1">Paul Kalas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Konopacky_Q/0/1/0/all/0/1">Quinn Konopacky</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Larkin_J/0/1/0/all/0/1">James E. Larkin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_E/0/1/0/all/0/1">Eve J. Lee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lin_J/0/1/0/all/0/1">Jonathan W. Lin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maire_J/0/1/0/all/0/1">Jerome Maire</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marchis_F/0/1/0/all/0/1">Franck Marchis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marois_C/0/1/0/all/0/1">Christian Marois</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Metchev_S/0/1/0/all/0/1">Stanimir Metchev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Millar_Blanchaer_M/0/1/0/all/0/1">Maxwell A. Millar-Blanchaer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Morzinski_K/0/1/0/all/0/1">Katie M. Morzinski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oppenheimer_R/0/1/0/all/0/1">Rebecca Oppenheimer</a>, et al. (18 additional authors not shown)

We present a statistical analysis of the first 300 stars observed by the
Gemini Planet Imager Exoplanet Survey (GPIES). This subsample includes six
detected planets and three brown dwarfs; from these detections and our contrast
curves we infer the underlying distributions of substellar companions with
respect to their mass, semi-major axis, and host stellar mass. We uncover a
strong correlation between planet occurrence rate and host star mass, with
stars M $>$ 1.5 $M_odot$ more likely to host planets with masses between 2-13
M$_{rm Jup}$ and semi-major axes of 3-100 au at 99.92% confidence. We fit a
double power-law model in planet mass (m) and semi-major axis (a) for planet
populations around high-mass stars (M $>$ 1.5M$_odot$) of the form $frac{d^2
N}{dm da} propto m^alpha a^beta$, finding $alpha$ = -2.4 $pm$ 0.8 and
$beta$ = -2.0 $pm$ 0.5, and an integrated occurrence rate of $9^{+5}_{-4}$%
between 5-13 M$_{rm Jup}$ and 10-100 au. A significantly lower occurrence rate
is obtained for brown dwarfs around all stars, with 0.8$^{+0.8}_{-0.5}$% of
stars hosting a brown dwarf companion between 13-80 M$_{rm Jup}$ and 10-100
au. Brown dwarfs also appear to be distributed differently in mass and
semi-major axis compared to giant planets; whereas giant planets follow a
bottom-heavy mass distribution and favor smaller semi-major axes, brown dwarfs
exhibit just the opposite behaviors. Comparing to studies of short-period giant
planets from the RV method, our results are consistent with a peak in
occurrence of giant planets between ~1-10 au. We discuss how these trends,
including the preference of giant planets for high-mass host stars, point to
formation of giant planets by core/pebble accretion, and formation of brown
dwarfs by gravitational instability.

We present a statistical analysis of the first 300 stars observed by the
Gemini Planet Imager Exoplanet Survey (GPIES). This subsample includes six
detected planets and three brown dwarfs; from these detections and our contrast
curves we infer the underlying distributions of substellar companions with
respect to their mass, semi-major axis, and host stellar mass. We uncover a
strong correlation between planet occurrence rate and host star mass, with
stars M $>$ 1.5 $M_odot$ more likely to host planets with masses between 2-13
M$_{rm Jup}$ and semi-major axes of 3-100 au at 99.92% confidence. We fit a
double power-law model in planet mass (m) and semi-major axis (a) for planet
populations around high-mass stars (M $>$ 1.5M$_odot$) of the form $frac{d^2
N}{dm da} propto m^alpha a^beta$, finding $alpha$ = -2.4 $pm$ 0.8 and
$beta$ = -2.0 $pm$ 0.5, and an integrated occurrence rate of $9^{+5}_{-4}$%
between 5-13 M$_{rm Jup}$ and 10-100 au. A significantly lower occurrence rate
is obtained for brown dwarfs around all stars, with 0.8$^{+0.8}_{-0.5}$% of
stars hosting a brown dwarf companion between 13-80 M$_{rm Jup}$ and 10-100
au. Brown dwarfs also appear to be distributed differently in mass and
semi-major axis compared to giant planets; whereas giant planets follow a
bottom-heavy mass distribution and favor smaller semi-major axes, brown dwarfs
exhibit just the opposite behaviors. Comparing to studies of short-period giant
planets from the RV method, our results are consistent with a peak in
occurrence of giant planets between ~1-10 au. We discuss how these trends,
including the preference of giant planets for high-mass host stars, point to
formation of giant planets by core/pebble accretion, and formation of brown
dwarfs by gravitational instability.

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