Joäo Manuel Da Silva Santos


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Works at Department of Astronomy
Telephone 08-553 785 15
Visiting address AlbaNova, Roslagstullsbacken 21 C, plan 6
Room D6:3019
Postal address Institutionen för astronomi 10691 Stockholm

About me

PhD student in the Solar Physics group.



A selection from Stockholm University publication database
  • 2018. Joäo Manuel da Silva Santos, Jaime de la Cruz Rodriguez, Jorrit Leenaarts. Astronomy and Astrophysics 620

    Context. High-resolution observations of the solar chromosphere at millimeter wavelengths are now possible with the Atacama Large Millimeter Array (ALMA), bringing with them the promise of tackling many open problems in solar physics. Observations from other ground and space-based telescopes will greatly benefit from coordinated endeavors with ALMA, yet the diagnostic potential of combined optical, ultraviolet and mm observations has remained mostly unassessed. Aims. In this paper we investigate whether mm-wavelengths could aid current inversion schemes to retrieve a more accurate representation of the temperature structure of the solar atmosphere. Methods. We performed several non-LTE inversion experiments of the emergent spectra from a snapshot of 3D radiation-MHD simulation. We included common line diagnostics such as Ca II K, 8542 angstrom and Mg II h and k, taking into account partial frequency redistribution effects, along with the continuum around 1.2 mm and 3 mm. Results. We find that including the mm-continuum in inversions allows a more accurate inference of temperature as function of optical depth. The addition of ALMA bands to other diagnostics should improve the accuracy of the inferred chromospheric temperatures between log tau similar to [-6, -4.5] where the Ca II and Mg II lines are weakly coupled to the local conditions. However, we find that simultaneous multiatom, non-LTE inversions of optical and UV lines present equally strong constraints in the lower chromosphere and thus are not greatly improved by the 1.2 mm band. Nonetheless, the 3 mm band is still needed to better constrain the mid-upper chromosphere.

Show all publications by Joäo Manuel Da Silva Santos at Stockholm University

Last updated: April 9, 2019

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