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I am a Sagan postdoctoral researcher at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, in the field of astrophysics. I defended my PhD Thesis on July 9, 2015 as part of the Institute for Research on Exoplanets at Université de Montréal.

Profile_MKI currently work on the identification of cold, planetary-mass objects that are isolated in space and thus not in orbit around a star. These objects are faint and can be located anywhere in the sky, which makes them hard to discover, however they will serve as valuable benchmarks to understand the atmospheres of giant exoplanets. This is true because they have physical properties such as temperature, clouds, surface gravity and atmospheric pressure, that are similar to those of giant exoplanets. Furthermore, the absence of a bright host star makes it much easier to study these isolated objects, once we know where they are located !

An additional goal of this project is to measure the initial mass function (i.e., the population fraction of stars and substellar objects of each mass) in young stellar groups at very small masses, which will inform us on whether these giant planet-like objects can form like stars, or if they are more likely exoplanets ejected from their stellar system.

Curriculum Vitae (updated more frequently than this web page)

ADS List of Refereed Publications 

Publication Statistics (you might need to hit “back” if you encounter an ADS error)

Refereed Publications

First-Author Publications : 7

  1. Boucher, A.. ; Lafrenière, D. ; Gagné, J. ; Malo, L. ; Faherty, J. K. ; Doyon, R. ; Chen, C. ; BANYAN. VIII. New Low-Mass Stars and Brown Dwarfs with Candidate Circumstellar Disks ; 2016 ; Accepted in ApJ ; arxiv:1608.08259.
  2. Robert, J. ; Gagné, J. ; Artigau, É. ; Lafrenière, D. ; Nadeau, D. ; Doyon, R. ; Malo, L. ; Albert, L. ; Simard, C. ; Bardalez Gagliuffi, D. C. ; Burgasser, A. J. ; A Brown Dwarf Census from the SIMP Survey ; 2016 ; Accepted in ApJ ; arxiv:1607.06117. A web page describing the SIMP survey.
  3. Lannier, J. ; Delorme, P. ; Lagrange, A. M. ; Borgniet, S. ; Rameau, J. ; Schlieder, J. E. ; Gagné, J. ; Bonavita, M. A. ; Malo, L. ; Chauvin, G. ; Bonnefoy, M. ; Girard, J. H. ; MASSIVE: A Bayesian Analysis of Giant Planet Populations Around Low-Mass Stars ; 2016 ; A&A in press.
  4. Schmidt, S. J. ; Shapee, B. J.; Gagné, J. ; Stanek, K. Z. ; Prieto, J. L. ; Holoien, T. W.-S. ; Kochanek, C. S. ; Chomiuk, L. ; Dong, S. ; Seibert, M. ; Strader, J. ; ASASSN-16AE: A Powerful White-Light Flare on an Early-L Dwarf ; 2016 ; Accepted in ApJL ; arxiv:1605.04313 ; [PDF].
  5. Faherty, J. K ; Riedel, A. R.; Cruz. K. L.; Gagné, J. ; Filippazzo, J. C. ; Lambrides. E. ; Fica, H. ; Weinberger, A. ; Thorstensen, J. R. ; Tinney, C. G. ; Baldassare, V. ; Lemonier, E. ; Rice, E. L. ; Population Properties of Brown Dwarf Analogs to Exoplanets ; 2016 ; Accepted in ApJ ; arxiv:1605.07927 ; [PDF].
  6. Kellogg, K. ; Metchev, S. ; Gagné, J. ; Faherty, J. K. ; The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog ; 2016 ; ApJL, 821, 15 ; arxiv:1603.08529 ; [PDF].
  7. Gagné, J. ; Plavchan, P. ; Gao, P. ; Anglada-Escude, G. ; Furlan, E. ; Davison, C. ; Tanner, A. ; Henry, T. J. ; Riedel, A. R. ; Brinkworth, C. ; Latham, D. ; Bottom, M. ; White, R. ; Mills, S. ; Beichman, C. ; Johnson, J. A. ; Ciardi, D. R. ; Wallace, K. ; Mennesson, B. ; von Braun, K. ; Vasisht, G. ; Prato, L. ; Kane, S. R. ; Mamajek, E. E. ; Walp, B. ; Crawford, T. J. ; Rougeot, R. ; Geneser, C. S. ; Catanzarite, J.; A High-Precision NIR Survey for RV Variable Low-Mass Stars ; 2016 ; ApJ, 822, 40 ; arxiv:1603.05998 ; [PDF].
  8. Gao, P. ; Plavchan, P. ; Gagné, J. ; Furlan, E. ; Bottom, M. ; Anglada-Escudé, G. ; White, R. ; Davison, C. ; Beichman, C. ; Brinkworth, C. ; Johnson, J. A. ; Ciardi, D. ; Wallace, J. ; Mennesson, B. ; von Braun, K. ; Vasisht, G. ; Prato, L. ; Kane, S. R. ; Tanner, A. ; Crawford, T. ; Latham, D. ; Rougeot, R. ; Geneser, C. ; Catanzarite, J. ; Retrieval of Precise Radial Velocities from Near-Infrared High Resolution Spectra of Low Mass Stars ; 2016 ; PASP in press ; arxiv:1603.05997 ; [PDF].
  9. Burgasser, A. J. ; Lopez, M. A. ; Mamajek, E. E. ; Gagné, J. ; Faherty, J. K. ; Tallis, M. ; Choba, C. ; Escala, I. ; Aganze, C. ; The First Brown Dwarf/Planetary-Mass Object in the 32 Orionis Group ; 2016 ; ApJ, 820, 32 ; arxiv:1602.03022 ; [PDF].
  10. Yi, X. ; Li, J. ; Diddams, S. ; Ycas, G. ; Plavchan, P. ; Leifer, S. ; Sandhu, J. ; Vasisht, G. ; Chen, P. ; Gao, P. ; Gagné, J. ; Demonstration of a near-IR line-referenced electro-optical laser frequency comb for precision radial velocity measurements in astronomy ; 2016 ; Nat Comms, vol. 7, p. 10436 ; arxiv:1501.02509 ; [PDF].
  11. Burgasser, A. J. ; Logsdon, S. E. ; Gagné, J. ; Bochanski, J. J. ; Faherty, J. K. ; West, A. A. ; Mamajek, E. E. ; Schmidt, S. J. ; Cruz, K. L. ; The Brown Dwarf Kinematics Project (BDKP). IV. Radial Velocities of 85 Late-M and L dwarfs with MagE. ; 2015 ; ApJS, 220, 18. arxiv:1507.00057 ; [PDF].
  12. Gagné, J. ; Faherty, J. K. ; Cruz, K. L. ; Lafrenière, D. ; Doyon, R. ; Malo, L. ; Burgasser, A. J. ; Naud, M.-E. ; Artigau, É. ; Bouchard, S. ; Gizis, J. E. ; BANYAN. VII. A New Population of Young Substellar Candidate Members of Nearby Moving Groups from the BASS Survey ; 2015 ; ApJS, 219, 33G ; arxiv:1506.07712 ; [PDF] – Link to scientific material.
  13. Gagné, J. ; Burgasser, A. J. ; Faherty, J. K. ; Lafrenière, D. ; Doyon, R. ; Filippazzo, J. C. ; Bowsher, E. ; Nicholls, C. P. ; SDSS J111010.01+011613.1: A New Planetary-Mass T Dwarf Member of the AB Doradus Moving Group ; 2015 ; ApJ, 808L, 20. arxiv:1506.04195 ; [PDF].
  14. Artigau, É. ; Gagné, J. ; Faherty, J. K. ; Malo, L. ; Naud, M.-E. ; Doyon, R. ; Lafrenière, D. ; BANYAN. VI. Discovery of a Companion at the Brown Dwarf/Planetary-Mass Limit to a Tucana-Horologium M Dwarf; 2015; ApJ, 806, 254 ; arxiv:1505.01747 ; [PDF].
  15. Lachapelle, F.-R. ; Lafrenière, D. ; Gagné, J. ; Jayawardhana, R. ; Janson, M. ; Helling, C., Witte, S. ; Characterization of Low-Mass, Wide-Separation Substellar Companions to Stars in Upper Scorpius: Near-Infrared Photometry and Spectroscopy; 2015; ApJ, 802, 61 ; arxiv:1503.07586 ; [PDF].
  16. Gagné, J. ; Lafrenière, D. ; Doyon, R. ; Malo, L. ; Artigau, É. ; BANYAN. V. A Systematic All-Sky Survey for New Very Late-Type Low-Mass Stars and Brown Dwarfs in Nearby Young Moving Groups; 2015; ApJ, 798, 73 ; arxiv:1410.4864 ; [PDF] –  Link to scientific material.
  17. Baron, F. ; Lafrenière, D. ; Artigau, É. ; Doyon, R. ; Gagné, J.Search and Characterization of Wide Binary Systems with a Very Low Mass Component; 2014; ApJ, 802, 37 ; arxiv:1501.05925 ; [PDF].
  18. Gagné, J. ; Lafrenière, D. ; Doyon, R. ; Artigau, É. ; Malo, L. ; Robert, J. ; Nadeau, D. ; SIMP J2154-1055: A New Low-Gravity L4β Brown Dwarf Candidate Member of the Argus Association; 2014; ApJ, 792, L17 ; arxiv:1407.5344 ; [PDF] –  Link to scientific material.
  19. Malo, L. ; Doyon, R. ; Feiden, G. A. ; Albert, L. ; Lafrenière, D. ; Artigau, É. ; Gagné, J. ; Riedel, A. R. ; BANYAN. IV. Fundamental parameters of low-mass star candidates in nearby young stellar kinematic groups – Isochronal Age determination using Magnetic evolutionary models; 2014; ApJ, 792, 37 ; arxiv:1406.6750 ; [PDF].
  20. Naud, M. È. ; Artigau, É. ; Malo, L. ; Albert, L. ; Doyon, R. ; Lafrenière, D. ; Gagné, J. ; Saumon, D. ;  Morley, C. ; Allard, F. ; Homeier, D. ; Boucher, A. ; Discovery of a Wide Planetary-Mass Companion to the Young M3 Star Gu Psc; 2014; ApJ, 787, 5 ; arxiv:1405.2932 ; [PDF].
  21. Gagné, J. ; Faherty, J. K. ; Cruz, K. ; Lafrenière, D. ; Doyon, R. ; Malo, L. ; Artigau, É. ; The Coolest Isolated Planetary-Mass Brown Dwarf Candidate Member of TWA; 2014; ApJ, 785, L14 ; arxiv:1403.3120 ; [PDF] – Link to scientific material.
  22. Malo, L. ; Artigau, É. ; Doyon, R. ; Lafrenière, D. ; Albert, L. ; Gagné, J.BANYAN. III. Radial Velocity, Rotation and X-ray Emission of Low-Mass Star Candidates in Nearby Young Kinematic Groups; 2014; ApJ, 788, 81M ; arxiv:1402.6053 ; [PDF].
  23. Gagné, J. ; Lafrenière, D. ; Doyon, R. ; Malo, L. ; Artigau, É. ; BANYAN. II. Very Low Mass and Substellar Candidate Members to Nearby, Young Kinematic Groups With Previously Known Signs of Youth; 2014; ApJ, 783, 121 ; arxiv:1312.5864 ; [PDF] – Link to scientific material.
  24. Delorme, P. ; Gagné, J. ; Girard, J. H. ; Lagrange, A. M. ; Chauvin, G.; Naud, M. È. ; Lafrenière, D. ; Doyon, R. ; Riedel, A. ; Bonnefoy, M. ; Malo, L. ; Direct-Imaging Discovery of a 12-14 Jupiter-Mass Object Orbiting A Young Binary System of Very Low-Mass Stars; 2013; A&A, 553L, 5D ; arxiv:1303.4525 ; [PDF]
  25. Malo, L. ; Doyon, R. ; Lafrenière, D. ; Artigau, É. ; Gagné, J. ; Baron, F. ; Riedel, A. ; [BANYAN. I.] Bayesian Analysis to Identify New Star Candidates in Nearby Young Stellar Kinematic Groups; 2013; ApJ, 762, 88M ; arxiv:1209.2077 ; [PDF].
  26. Delorme, P. ; Gagné, J. ; Malo, L. ; Reylé, C. ; Artigau, É. ; Albert, L. ; Forveille, T.; Delfosse, X.; Allard, F.; Homeier, D.; CFBDSIR2149-0403: A 4-7 Jupiter-Mass Free-Floating Planet in the Young Moving Group AB Doradus ?; 2012; A&A, 548A, 26D ; arxiv:1210.0305 ; [PDF].
  27. Artigau, É. ; Lafrenière, D. ; Doyon, R. ; Liu, M. ; Dupuy, Trent ; Albert, L. ; Gagné, J. ; Malo, L. ; Gratadour, D. ; Discovery of Two L and T Binaries with Wide Separations and Peculiar Photometric Properties ; 2011; ApJ, 739, 48-61 ; arxiv:1107.0768 ; [PDF].

Professional Memberships

More Details on my Scientific Projects

My main scientific interests are young, low-mass brown dwarfs in the solar neighborhood. I use known young (~8-150 Myr) associations to calibrate their age and investigate their physical properties using various tools such as photometry and spectroscopy. This work aims at improving our knowledge on the initial mass function in the planetary-mass regime, as well as better understanding the atmospheric properties of giant, gaseous exoplanets using planetary-mass objects isolated in space.

A detailed description of my PhD thesis is available here.

My current main scientific project is leading the BASS-Ultracool survey, for which I have been awarded a Sagan Fellowship (taking place at Carnegie DTM, September 2015-2018). The project  consists in the following points ;

  1. Improving the BANYAN II tool to include a larger number of young moving groups, make it more CPU-efficient, and correctly account for variable dependencies within a Bayesian framework.
  2. Creating a cross-match algorithm based on Bayes’ theorem and use it to cross-match not only 2MASS and AllWISE, but also UKIDSS and the 2MASS-Reject point source catalogs. The main goal of this step is to identify very late-type (> L5) , cool members of young moving groups.
  3. The candidate members identified in step 2 will have masses well into the planetary regime (~2-12 M_Jup). A near-infrared low-resolution spectroscopic follow-up at Magellan-Baade using FIRE will allow the rejection of non-ultracool dwarf contaminants.
  4. We will use the Echelle mode of the FIRE spectrograph to measure the radial velocity of the most promising candidate members, and lead a parallax follow-up campaign with FourStar to provide the final confirmation of their membership, and thus planetary mass.

A PDF description of my postdoctoral project is available here.

This project has already allowed us to identify the coolest isolated member of any young moving group known to date, SDSS J1110+0119, which is an 11 M_Jup T5.5 dwarf in AB Doradus. The scientific paper describing this discovery can be found here.

I have also been working with Peter Plavchan on a precise near-infrared survey for radial velocity variations of young and nearby M dwarfs, using the CSHELL spectrometer at IRTF. We have recently submitted the survey paper to the Astrophysical Journal.

Conference Proceedings

  1. Gagné, J. ; Lafrenière, D. ; Doyon, R. ; Faherty, J. K. ; Malo, L. ; Cruz, K. L. ; Artigau, É. ; Burgasser, A. J. ; Naud, M.-E. ; Bouchard, S. ; Gizis, J. E. ; Albert, L. ; The BANYAN All-Sky Survey for Brown Dwarf Members of Young Moving Groups; 2014;  Proceedings of the IAU; IAU 314 on Young Stars & Planets Near the Sun (Atlanta, GA, US, May 10-14 2015). arxiv:1506.04193
  2. Yi X. ; Vahala K. ; Diddams S. ; Ycas G. ; Plavchan P. ; Leifer S. ; Sandhu J. ; Vasisht G. ; Chen P. ; Gao P. ; Gagné, J. ; Furlan E. ; Bottom M. ; Martin E. ; Fitzgerald M. ; Doppmann G. ; Beichman C. ; Demonstration of a Near-IR Laser Comb for Precision Radial Velocity Measurements in Astronomy; 2015; arxiv:1501.02509
  3. Gagné, J. ; Lafrenière, D. ; Doyon, R. ; Faherty, J. ; Malo, L. ; Artigau, É. ; Results from BASS, the BANYAN All-Sky Survey; 2014;  Proceedings of Lowell Observatory. arxiv:1410.3072
  4. Malo, L. ; Gagné, J.  ; Doyon, R. ; Lafrenière, D. ; Artigau, É. ; Albert, L. ; Prospects for the BANYAN search of low-mass moving group members with GAIA, and the importance of magnetic fields for isochronal age determination; 2014;  Submitted to Mem. S. A. It.
  5. Gagné, J. ; Lafrenière, D. ; Doyon, R. ; Malo, L. ; Faherty, J. ; Artigau, É. ; Bayesian Analysis to Identify Very Low-Mass Members of Nearby Young Stellar Kinematic Groups; 2013;  Mem. S. A. It. Vol. 84, 916arxiv:1307.1127.
  6. Delorme, P. ; Gagné, J. ; Lannier, J. ; Lagrange, A. M. ; Chauvin, G. ; Brown Dwarfs or Planets ? Some Direct Imaging Detections that Blur the Border; 2013; Mem. S. A. It. Vol. 84, 1013.
  7. Naud, M. È. ; Artigau, É. ; Doyon, R. ; Malo, L. ; Albert, L. ; Lafrenière, D. ; Gagné, J. ; A Wide Planetary-Mass Companion to a Young M3 Star of the AB Dor Moving Group; 2013;  EPJ Web of Conferences; 2013EPJWC..4713004N.
  8. Maire, J. ; Gagné, J. ; Lafrenière, D. ; Graham, J. R. ; Doyon, R. ; High-Fidelity Photometry and Astrometry of High-Contrast Imaged Companions Using LOCI Processing; 2013 ; Proceedings of the International Astronomical Union 8 (S299), 44-45.
  9. Maire, J. ; Gagné, J. ; Lafrenière, D. ; Doyon, R. ; Graham, J. R. ; Véran, J. P. ; Poyneer, L. A. ; Preserving the Photometric Integrity of Companions in High-Contrast Imaging Observations Using Locally Optimized Combination of Images; 2012 ; Proc. SPIE 8447, Adaptive Optics Systems III, 844760 D.

Poster Presentations

  1. Montreal, Qc, CA – 2015. In the Spirit of Lyot Symposium. SDSS 1110+0116 : A New T Dwarf member of AB Doradus. – Figshare
  2. Pasadena, California – 2014. Sagan Summer Workshop. The search for brown dwarfs in young moving groups – Figshare
  3. Flagstaff, Arizona – 2014. Cool Stars 18 Symposium. The search for brown dwarfs in young moving groups – Figshare
  4. Barcelone, Spain – 2012. Symposium Cool Stars 17The search for brown dwarfs in young moving groups.
  5. Montreal, Qc, CA – 2012 Journée Annuelle de la Recherche des Étudiants en Physique de l’UdeM(JAREPUM) symposiumThe search for brown dwarfs in young moving groups. (French)
  6. Montreal, Qc, CA – 2011. Journée Annuelle de la Recherche des Étudiants en Physique de l’UdeM(JAREPUM) symposiumDirect imaging of exoplanets with the LOCI algorithm. (French)

Web Publications

  1. The iOS application Brown Dwarf Converter – Astrobetter – Link.
  2. Guide for developing an iOS application – Astrobetter – Link.

Collaborators

  • Jacqueline K. Faherty – Carnegie Institute/AMNH – Washington D.C., US – Web page.
  • Kelle L. Cruz – AMNH – New-York, US – Web Page.
  • David Lafrenière – iREx/UdeM – Montréal, Canada – Web Page.
  • René Doyon – iREx/UdeM – Montréal, Canada – Web Page.
  • Peter Plavchan – Missouri State University – Springfield, US – Web Page.
  • Étienne Artigau – iREx/UdeM – Montréal, Canada – Web Page.
  • Lison Malo – CFHT/iREx – Waimea, US – Web Page.
  • Loïc Albert – iREx/UdeM – Montréal, Canada – Web Page.
  • Philippe Delorme – IPAG – Grenoble, France – Web Page.
  • Adam J. Burgasser – UCSD – San Diego, US – Web Page.
  • David Rodriguez – Universidad de Chile – Santiago, Chile – Web Page.
  • Adric Riedel –  AMNH –  New-York, US – Web Page.
  • Brendan P. Bowler – Caltech – Pasadena, US – Web Page.
  • Peter Gao – Caltech – Pasadena, US – Web Page.
  • Erini Lambrides – AMNH – New-York, US
  • Joseph C. Filippazzo – AMNH – New-York, US
  • François-René Lachapelle – iREx/UdeM – Montréal, CA – Web Page.
  • Frédérique Baron – iREx/UdeM – Montréal, CA – Web Page.
  • Daniella Bardalez Gagliuffi – UCSD – San Diego, US – Web Page.
  • Jacqueline Radigan – University of Toronto – Toronto, Canada – Web Page.
  • Joshua Schlieder – Max Planck Insitute for Astronomy – Heidelberg, Germany – Web Page.

Scientific Material Related to my Publications

  • Gagné et al. 2014a ; BANYAN II and known, young brown dwarfs – Link.
  • Gagné et al. 2014b ; The discovery of a L1-type brown dwarf in TW Hydrae – Link.
  • Gagné et al. 2014c ; An L4β candidate member of Argus – Link.
  • Gagné et al. 2015a ; BANYAN V, the BASS survey – Link.
  • Gagné et al. 2015c ; BANYAN VII, a NIR follow-up of the BASS survey  – Link.
  • The BANYAN II web tool – Link.
  • The Montreal Spectral Library – Link.

IDL Programs

  • FireHose V2, an updated IDL pipeline to reduce FIRE data – Link.
  • Red Flamingos, an IDL pipeline to reduce Flamingos 2 data – Link.
  • To estimate the mass of a low-mass star or brown dwarf, using 2MASS / WISE photometry, age and distance – Link.
  • To use the API web service of Astrometry.net – Link.
  • To use a local implementation of Astrometry.net with IDL – Link.
  • To perform web queries to the SIMBAD service – Link.
  • To combine measurements with individual errors – Link.
  • To compute XYZ and UVW Galactic coordinates with error propagation – Link.
  • To fit scatter data points with a 3D ellipsoid free to rotate around three Euler angles – Link.
  • To perform a 3D rotation on cartesian coordinates with error propagation – Link.
  • To transform Euler angles into rotation matrices, and vice-versa – Link.
  • An example IDL routine to generate a figure for spectral comparison (Figure 1, Gagné et al. 2014b) – Link.

Miscellaneous Scientific Material

  • The RIZzo spectral library ; red-optical spectra of 800+ ultracool objects – Link.
  • A list of current members to nearby, young moving groups (as of december 2013) – Link.
  • A list of known young field brown dwarfs (as of december 2013) – Link.
  • An iOS application to convert the mass / temperature / spectral type / etc. for brown dwarfs – Link.
  • User manual for the Astrometry.net service – Link.
  • User manual for the SIMON spectrograph and imager at the CTIO-1.5m – Link.
  • The Bible of Physics (French) – Link.
  • About the problematic membership of Kappa Andromeda to the Columba association – Link.
  • The DwarfArchive (containing a list of M, L and T dwarfs) – Link.
  • Gregory Mace’s Web Page – See Table 6.4 in his thesis for a census of all L+ brown dwarfs as of early February 2014 – Link.
  • The Astrometry.net service – Link.
  • The AstroBetter blog maintained by Kelle Cruz – Link.
  • The BDNYC blog, maintained by the BDNYC research group at AMNH (Anglais) – Link.
  • The IRSA service to create Finder Charts and perform 2MASS and WISE queries – Link.
  • The Wolfram Alpha service, to (amongst others) stop worrying about physical units when you do physics – Link.
  • The astronomical applications developed by Cédric Foellmi – Link.

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