Seminar: A High Resolution H- and K-Band Spectroscopic Sequence of Ultracool Dwarfs

  • Date: –15:00
  • Location: Cyberspace
  • Lecturer: Jennifer Greco
  • Website
  • Contact person: Sofia Ramstedt
  • Seminarium

Brown dwarfs are substellar objects of too low mass to initiate the hydrogen fusion necessary to be considered stars. We have obtained the first high-resolution (R ∼ 45,000) H- and K-band spectral sequence of ultracool dwarfs with spectral types ranging from M1.5 V to T6, including known low-gravity objects at six spectral types (M9, L0, L1, L2, L3, L5). All spectra were obtained using the Immersion Grating INfrared Spectrometer (IGRINS) at a resolving power of R ∼ 45,000. We compared 22 of our objects to synthetic spectra created from the atmospheric models of Saumon & Marley (2008), to measure specific properties including effective temperature, cloud properties, rotational velocities, and surface gravity.

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We will run with the following setup:
- The zoom meeting will open at 13.45 so that you can log on and try it out.
- Participants should mute their microphones unless they have a question.
- Questions are allowed during the talk. Just raise your hand in the zoom app.
- After the talk has finished, unmute for applause.
- If possible, keep your video on during the full seminar so that the speaker gets visual feedback while talking.
- Questions after the talk will be administered as follows; raise your hand in the app and Sofia will chair and give the word.

- Finally, after the talk and question sessions are finished, the meeting will remain open for an informal ”bring-your-own-fika” if you want to hang around and chat with your colleagues and the speaker.