Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWST
Free-floating planetary-mass objects (FFPMOs) are known to harbor disks at young ages. Here, we present 1–13 μ m spectra for eight young FFPMOs with masses of 5–10 M _Jup (at ages of 1–5 Myr), using the NIRSpec and MIRI instruments on the James Webb Space Telescope. We derive fundamental properties...
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astronomical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-3881/adea50 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849728200287977472 |
|---|---|
| author | Belinda Damian Aleks Scholz Ray Jayawardhana V. Almendros-Abad Laura Flagg Koraljka Mužić Antonella Natta Paola Pinilla Leonardo Testi |
| author_facet | Belinda Damian Aleks Scholz Ray Jayawardhana V. Almendros-Abad Laura Flagg Koraljka Mužić Antonella Natta Paola Pinilla Leonardo Testi |
| author_sort | Belinda Damian |
| collection | DOAJ |
| description | Free-floating planetary-mass objects (FFPMOs) are known to harbor disks at young ages. Here, we present 1–13 μ m spectra for eight young FFPMOs with masses of 5–10 M _Jup (at ages of 1–5 Myr), using the NIRSpec and MIRI instruments on the James Webb Space Telescope. We derive fundamental properties of these targets, and find spectral types of M9.5 to L4, with effective temperatures of 1600–1900 K. The photospheric spectra of our targets show a clear diversity at similar temperatures, especially in the 3–5 μ m range, unaccounted for by existing atmospheric models. We find a silicate absorption feature in the photosphere of one of our targets, the first such detection in very young FFPMOs, indicating silicate clouds in their cool atmospheres. Six of our objects show mid-infrared excess emission above the photosphere, as well as silicate emission features, demonstrating the presence of disks. The shape and strength of the latter features constitute strong evidence of grain growth and crystallization, similar to what is seen in more massive brown dwarfs and stars. We also detect emission lines from hydrocarbon molecules in the disks of several targets. These are the lowest-mass isolated objects found so far with silicate and hydrocarbon emission features arising in their disks. The presence of disks and their characteristics point to the potential for the formation of rocky companions around free-floating planetary-mass objects. |
| format | Article |
| id | doaj-art-986c0fdd27964ccf9bdfb604006f23fe |
| institution | DOAJ |
| issn | 1538-3881 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj-art-986c0fdd27964ccf9bdfb604006f23fe2025-08-20T03:09:36ZengIOP PublishingThe Astronomical Journal1538-38812025-01-01170212710.3847/1538-3881/adea50Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWSTBelinda Damian0https://orcid.org/0000-0002-2234-4678Aleks Scholz1https://orcid.org/0000-0001-8993-5053Ray Jayawardhana2https://orcid.org/0000-0001-5349-6853V. Almendros-Abad3https://orcid.org/0000-0002-4945-9483Laura Flagg4https://orcid.org/0000-0001-6362-0571Koraljka Mužić5https://orcid.org/0000-0002-7989-2595Antonella Natta6https://orcid.org/0000-0002-4608-7995Paola Pinilla7https://orcid.org/0000-0001-8764-1780Leonardo Testi8https://orcid.org/0000-0003-1859-3070SUPA, School of Physics & Astronomy, University of St Andrews , North Haugh, St Andrews KY16 9SS, UK ; bd64@st-andrews.ac.ukSUPA, School of Physics & Astronomy, University of St Andrews , North Haugh, St Andrews KY16 9SS, UK ; bd64@st-andrews.ac.ukDepartment of Physics & Astronomy, Johns Hopkins University , Baltimore, MD 21218, USAIstituto Nazionale di Astrofisica (INAF)—Osservatorio Astronomico di Palermo , Piazza del Parlamento 1, 90134, Palermo, ItalyDepartment of Physics & Astronomy, Johns Hopkins University , Baltimore, MD 21218, USAInstituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências, Universidade de Lisboa , Ed. C8, Campo Grande, 1749-016 Lisbon, PortugalSchool of Cosmic Physics, Dublin Institute for Advanced Studies , 31 Fitzwilliam Place, Dublin 2, IrelandMullard Space Science Laboratory, University College London , Holmbury St Mary, Dorking, Surrey, UKDipartimento di Fisica e Astronomia, Università di Bologna , Via Gobetti 93/2, 40122, Bologna, ItalyFree-floating planetary-mass objects (FFPMOs) are known to harbor disks at young ages. Here, we present 1–13 μ m spectra for eight young FFPMOs with masses of 5–10 M _Jup (at ages of 1–5 Myr), using the NIRSpec and MIRI instruments on the James Webb Space Telescope. We derive fundamental properties of these targets, and find spectral types of M9.5 to L4, with effective temperatures of 1600–1900 K. The photospheric spectra of our targets show a clear diversity at similar temperatures, especially in the 3–5 μ m range, unaccounted for by existing atmospheric models. We find a silicate absorption feature in the photosphere of one of our targets, the first such detection in very young FFPMOs, indicating silicate clouds in their cool atmospheres. Six of our objects show mid-infrared excess emission above the photosphere, as well as silicate emission features, demonstrating the presence of disks. The shape and strength of the latter features constitute strong evidence of grain growth and crystallization, similar to what is seen in more massive brown dwarfs and stars. We also detect emission lines from hydrocarbon molecules in the disks of several targets. These are the lowest-mass isolated objects found so far with silicate and hydrocarbon emission features arising in their disks. The presence of disks and their characteristics point to the potential for the formation of rocky companions around free-floating planetary-mass objects.https://doi.org/10.3847/1538-3881/adea50Free floating planetsProtoplanetary disksInfrared excessJames Webb Space TelescopeInfrared spectroscopy |
| spellingShingle | Belinda Damian Aleks Scholz Ray Jayawardhana V. Almendros-Abad Laura Flagg Koraljka Mužić Antonella Natta Paola Pinilla Leonardo Testi Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWST The Astronomical Journal Free floating planets Protoplanetary disks Infrared excess James Webb Space Telescope Infrared spectroscopy |
| title | Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWST |
| title_full | Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWST |
| title_fullStr | Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWST |
| title_full_unstemmed | Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWST |
| title_short | Spectroscopy of Free-floating Planetary-mass Objects and Their Disks with JWST |
| title_sort | spectroscopy of free floating planetary mass objects and their disks with jwst |
| topic | Free floating planets Protoplanetary disks Infrared excess James Webb Space Telescope Infrared spectroscopy |
| url | https://doi.org/10.3847/1538-3881/adea50 |
| work_keys_str_mv | AT belindadamian spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT aleksscholz spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT rayjayawardhana spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT valmendrosabad spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT lauraflagg spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT koraljkamuzic spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT antonellanatta spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT paolapinilla spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst AT leonardotesti spectroscopyoffreefloatingplanetarymassobjectsandtheirdiskswithjwst |