prikaz prve stranice dokumenta Atmospheric characterization of young L- and T- dwarfs
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master's thesis
Atmospheric characterization of young L- and T- dwarfs
2024. urn:nbn:hr:166:555169
Bašić, Martina
University of Split
Faculty of Science

Cite this document

Bašić, M. (2024). Atmospheric characterization of young L- and T- dwarfs (Master's thesis). Split: University of Split, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:166:555169

Bašić, Martina. "Atmospheric characterization of young L- and T- dwarfs." Master's thesis, University of Split, Faculty of Science, 2024. https://urn.nsk.hr/urn:nbn:hr:166:555169

Bašić, Martina. "Atmospheric characterization of young L- and T- dwarfs." Master's thesis, University of Split, Faculty of Science, 2024. https://urn.nsk.hr/urn:nbn:hr:166:555169

Bašić, M. (2024). 'Atmospheric characterization of young L- and T- dwarfs', Master's thesis, University of Split, Faculty of Science, accessed 20 November 2024, https://urn.nsk.hr/urn:nbn:hr:166:555169

Bašić M. Atmospheric characterization of young L- and T- dwarfs [Master's thesis]. Split: University of Split, Faculty of Science; 2024 [cited 2024 November 20] Available at: https://urn.nsk.hr/urn:nbn:hr:166:555169

M. Bašić, "Atmospheric characterization of young L- and T- dwarfs", Master's thesis, University of Split, Faculty of Science, Split, 2024. Available at: https://urn.nsk.hr/urn:nbn:hr:166:555169

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Metadata
TitleAtmospheric characterization of young L- and T- dwarfs
Title (croatian)Atmosferske karakteristike mladih patuljaka tipa L i T
AuthorMartina Bašić
MentorKoraljka Mužić (mentor)
Committee memberKoraljka Mužić (predsjednik povjerenstva)
Committee memberMarko Kovač (član povjerenstva)
Committee memberTamara Rom (član povjerenstva)
GranterUniversity of Split
Faculty of Science
Split
Defense date and country2024-09-27, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Physics
Abstract
Young brown dwarfs with L and T spectral types primarily emit in the near-infrared wavelengths. Their spectral energy distribution is heavily influenced by atmospheric conditions, including temperature, gravity, and molecule condensation. In this study, we aim to determine the effective temperature and surface gravity of 34 brown dwarfs located in nearby young moving groups and star-forming regions. We derived the characteristics of these objects by comparing their observed spectra, obtained with the X-shooter instrument on the VLT, to atmospheric model spectra. Two models were used for comparison: the cloudless ATMO model and the cloudy BT-Settl-CIFIST model. The best-fit effective temperature and surface gravity for each object were determined using the least squares method. These parameters were then used to estimate the mass and radius of the brown dwarfs. The analysis revealed that the BT-Settl-CIFIST model more accurately fits the spectra of L-type dwarfs, while the ATMO model is better suited for T-type dwarfs. The effective temperatures generally decrease with later spectral types but mostly cluster around 1800 K and 1700 K for objects classified between L0 and L5. Most objects have masses above 3 \(M_{J}\), the expected lower mass limit for their spectral types, although some fall below this threshold. The radius of the objects depends on the dilution factor derived from matching the observed and model spectra.
Abstract (croatian)
Mladi smeđi patuljci sa spektralnim tipovima L i T prvenstveno emitiraju u bliskom infracrvenom području. Njihova raspodjela spektralne energije uvelike je pod utjecajem atmosferskih uvjeta, uključujući temperaturu, gravitaciju i kondenzaciju molekula. U ovom radu želimo odrediti efektivnu temperaturu i površinsku gravitaciju 34 smeđa patuljka smještenih u obližnjim mladim pokretnim skupinama i područjima stvaranja zvijezda. Karakteristike ovih objekata dobivene su usporedbom njihovih promatranih spektara, dobivenih instrumentom X-shooter na Vrlo velikom teleskopu (VLT-u), sa spektrima atmosferskih modela. Za usporedbu su korištena dva atmosferska modela: model ATMO bez oblaka i model BT-Settl-CIFIST s oblacima. Najbolje odgovarajuće vrijednosti efektivne temperature i površinske gravitacije za svaki objekt određene su metodom najmanjih kvadrata te su ti parametri korišteni za procjenu mase i radijusa. Analiza je pokazala da model BT-Settl-CIFIST preciznije odgovara spektrima L-tipova, dok je ATMO prikladniji za T-tipove patuljaka. Efektivne temperature općenito opadaju s kasnijim spektralnim tipovima, ali se uglavnom grupiraju oko 1800 K i 1700 K za objekte klasificirane izmedu L0 i L5. Većina objekata ima mase iznad 3 \(M_{J}\), što je očekivana donja granica za njihove spektralne tipove, iako neki padaju ispod ovog praga. Radijus objekata ovisi o faktoru razrjeđenja dobivenom usklađivanjem promatranog spektra i spektra modela spektra.
Keywords
Keywords (croatian)
Languageenglish
URN:NBNurn:nbn:hr:166:555169
Study programmeTitle: Physics; specializations in: specialization in Education, specialization in Astrophysics and Elementary Particle Physics, specialization in Biophysics, specialization in Environmental Physics, specialization in Computational Physics
Course: specialization in Astrophysics and Elementary Particle Physics
Study programme type: university
Study level: graduate
Academic / professional title: sveučilišni/a magistar/magistra fizike (sveučilišni/a magistar/magistra fizike)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Terms of useLicence In copyright icon
Created on2024-10-23 11:57:29