Naslov
Differences in physical properties of coronal hole and quiet Sun coronal bright points and their ALMA counterparts

Autori
Matković, Filip

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
Meeting of ALMA Young Astronomers

Mjesto i datum
Online ; Düsseldorf, Njemačka, 06.03.2023. - 10.03.2023

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
corona ; coronal bright point ; UV radiation ; plasma ; radio radiation

Sažetak
Coronal bright points (CBPs) are a fundamental class of solar activity phenomenon. They represent a set of small-scale loops in the low corona that have an enhanced ultraviolet (UV)/extreme- ultraviolet (EUV) and X-ray emissions, but also radio emission as well. Thanks to the construction of the Atacama Large Millimeter/submillimeter Array (ALMA), detailed studies of the chromospheric features of a CBP are now possible. This is of crucial importance for getting a whole picture of a CBP and the physical mechanisms contained there. Using full-disk Band 6 (λ = 1.21 mm) radio data obtained by ALMA with EUV 193 Å and magnetogram data obtained by the Solar Dynamics Observatory (SDO), we report measurements of the mean intensity and projected area of CBPs within five coronal holes (CHs) and in the quiet Sun (QS) regions outside the CHs observed at different times near the centre of the solar disk. CBPs were firstly identified based on EUV and magnetogram data and are then identified in the corresponding ALMA data. Measurements of the intensity and area of the detected CBPs were conducted for both ALMA Band 6 and SDO EUV images. Then, an unequal variances t-test was conducted on randomly chosen CBP samples using a bootstrap technique to determine if CH and QS CBPs show any differences in the measured physical properties. Statistical analysis of the measured physical properties revealed that CBPs within CHs have on average a significantly lower mean intensity as well as a lower area than the QS CBPs. This was seen not only in the coronal parts of the CBP loop structure observed by SDO, but also in the chromospheric parts observed by ALMA. Future studies will focus on the evolution of the physical properties (intensity, morphology, and magnetic field) of both CBPs and CHs in order to investigate possible reasons for the observed differences between CBPs situated in different regions, but also to study how the coronal and chromospheric parts of a CBP loop structure might be linked.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA