scholarly journals Photometric data analysis: the estimation of interstellar extinction

2020 ◽  
pp. 322-326
Author(s):  
О.Ю. Малков ◽  
О.Б. Длужневская ◽  
А.О. Жуков ◽  
А.И. Захаров ◽  
Д.А. Ковалева ◽  
...  
Keyword(s):  
Data Analysis ◽  
Interstellar Extinction ◽  
Photometric Data ◽  
Multicolor Photometry

Учет межзвездного поглощения - необходимый этап в процессе параметризации звезд по многоцветной фотометрии. Мы анализируем опубликованные законы межзвездного поглощения и обсуждаем возможность оценки величины межзвездного поглощения для фотометрических полос современных больших обзоров. Taking into account interstellar extinction is the necessary procedure in the process of parameterization of stars from multicolor photometry. We analyze published interstellar extinction laws and discuss the possibility of assessing the interstellar extinction in photometric bands of modern large surveys.

scholarly journals Interstellar extinction from photometric surveys: application to four high-latitude areas

2018 ◽  
Vol 27 (1) ◽  
pp. 62-69 ◽  
Author(s):  
Oleg Malkov ◽  
Sergey Karpov ◽  
Elena Kilpio ◽  
Sergey Sichevsky ◽  
Dmitry Chulkov ◽  
...  
Keyword(s):  
High Latitude ◽  
Interstellar Extinction ◽  
Virtual Observatory ◽  
Multicolor Photometry

Abstract Information on interstellar extinction and dust properties may be obtained from modern large photometric surveys data. Virtual Observatory facilities allow users to make a fast and correct cross-identification of objects from various surveys. It yields a multicolor photometry data on detected objects and makes it possible to estimate stellar parameters and calculate interstellar extinction. A 3D extinction map then can be constructed. The method was applied to 2MASS, SDSS, GALEX and UKIDSS surveys. Results for several high-latitude areas are obtained, compared with independent sources and discussed here.

Interstellar Extinction from Large Surveys

2003 ◽  
Vol 12 (4) ◽  
Author(s):  
O. Yu. Malkov
Keyword(s):  
Survey Data ◽  
Extinction Ratio ◽  
Interstellar Extinction ◽  
Galactic Latitude ◽  
Virtual Observatory ◽  
Multicolor Photometry ◽  
Selective Extinction

AbstractUnder some assumptions, information on interstellar extinction may be obtained from modern large photometric survey data. Virtual Observatory facilities allow users to make a fast and correct cross-identification of objects from various surveys. This process yields multicolor photometry data for registered objects and makes it possible to estimate color excesses and, with a few exceptions for some areas with high total-to-selective extinction ratio, calculate interstellar extinction. A 3D extinction map then can be constructed for almost the whole sky. The method is applied to an area with the low Galactic latitude, and the results are discussed in the present paper.

scholarly journals Estimating Stellar Parameters and Interstellar Extinction from Evolutionary Tracks

2016 ◽  
Vol 25 (1) ◽  
Author(s):  
S. Sichevsky ◽  
O. Malkov
Keyword(s):  
Main Sequence ◽  
Formation Rate ◽  
Interstellar Extinction ◽  
Mass Function ◽  
Initial Mass Function ◽  
Stellar Atmospheres ◽  
Red Giants ◽  
Main Sequence Stars ◽  
Stellar Radius ◽  
Multicolor Photometry

AbstractDeveloping methods for analyzing and extracting information from modern sky surveys is a challenging task in astrophysical studies. We study possibilities of parameterizing stars and interstellar medium from multicolor photometry performed in three modern photometric surveys: GALEX, SDSS, and 2MASS. For this purpose, we have developed a method to estimate stellar radius from effective temperature and gravity with the help of evolutionary tracks and model stellar atmospheres. In accordance with the evolution rate at every point of the evolutionary track, star formation rate, and initial mass function, a weight is assigned to the resulting value of radius that allows us to estimate the radius more accurately. The method is verified for the most populated areas of the Hertzsprung-Russell diagram: main-sequence stars and red giants, and it was found to be rather precise (for main-sequence stars, the average relative error of radius and its standard deviation are 0.03% and 3.87%, respectively).

scholarly journals Verification of Photometric Parallaxes with Gaia DR2 Data

Galaxies ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Oleg Malkov ◽  
Sergey Karpov ◽  
Dana Kovaleva ◽  
Sergey Sichevsky ◽  
Dmitry Chulkov ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
High Latitude ◽  
Interstellar Extinction ◽  
Photometric Data ◽  
Sloan Digital Sky Survey ◽  
Combined Analysis ◽  
Luminosity Class ◽  
Sky Survey ◽  
Gaia Dr2

Results of comparison of Gaia DR2 parallaxes with data derived from a combined analysis of 2MASS (Two Micron All-Sky Survey), SDSS (Sloan Digital Sky Survey), GALEX (Galaxy Evolution Explorer), and UKIDSS (UKIRT Infrared Deep Sky Survey) surveys in four selected high-latitude | b | > 48° sky areas are presented. It is shown that multicolor photometric data from large modern surveys can be used for parameterization of stars closer than 4400 pc and brighter than g S D S S = 19 . m 6 , including estimation of parallax and interstellar extinction value. However, the stellar luminosity class should be properly determined.

scholarly journals Verification of photometric parallaxes with Gaia DR2 data

2018 ◽  
Author(s):  
Oleg Malkov ◽  
Sergey Karpov ◽  
Dana Kovaleva ◽  
Sergey Sichevsky ◽  
Dmitry Chulkov ◽  
...  
Keyword(s):  
High Latitude ◽  
Interstellar Extinction ◽  
Photometric Data ◽  
Combined Analysis ◽  
Gaia Dr2

We present the result of comparison of Gaia DR2 parallaxes and photometry with data derived from a combined analysis of 2MASS, SDSS, GALEX, and UKIDSS surveys in four selected high-latitude sky areas. We have shown that, under certain circumstances, multicolor photometric data from large modern surveys can be successfully used for parameterization of stars, including estimation of distance and interstellar extinction value.

Microchemical imaging in biomedical research

1992 ◽  
Vol 50 (2) ◽  
pp. 1118-1119
Author(s):  
P. Ingram
Keyword(s):  
Data Analysis ◽  
Electron Probe ◽  
The Other ◽  
X Ray ◽  
Cell Element ◽  
Physiological Information ◽  
Functional States ◽  
Elemental Maps ◽  
Electron Energy Loss ◽  
Secondary Ion

It is well established that unique physiological information can be obtained by rapidly freezing cells in various functional states and analyzing the cell element content and distribution by electron probe x-ray microanalysis. (The other techniques of microanalysis that are amenable to imaging, such as electron energy loss spectroscopy, secondary ion mass spectroscopy, particle induced x-ray emission etc., are not addressed in this tutorial.) However, the usual processes of data acquisition are labor intensive and lengthy, requiring that x-ray counts be collected from individually selected regions of each cell in question and that data analysis be performed subsequent to data collection. A judicious combination of quantitative elemental maps and static raster probes adds not only an additional overall perception of what is occurring during a particular biological manipulation or event, but substantially increases data productivity. Recent advances in microcomputer instrumentation and software have made readily feasible the acquisition and processing of digital quantitative x-ray maps of one to several cells.

Perceptions of a Collaborative Professional Learning Program: Seeing the “Bigger Picture”

2020 ◽  
Vol 5 (1) ◽  
pp. 290-303
Author(s):  
P. Charlie Buckley ◽  
Kimberly A. Murza ◽  
Tami Cassel
Keyword(s):  
Data Analysis ◽  
Professional Learning ◽  
Social Communication ◽  
Special Educators ◽  
Service Providers ◽  
Integrative Approach ◽  
Theory Approach ◽  
Learning Program ◽  
Speech Language Pathologists ◽  
Related Service

Purpose The purpose of this study was to explore the perceptions of special education practitioners (i.e., speech-language pathologists, special educators, para-educators, and other related service providers) on their role as communication partners after participation in the Social Communication and Engagement Triad (Buckley et al., 2015 ) yearlong professional learning program. Method A qualitative approach using interviews and purposeful sampling was used. A total of 22 participants who completed participation in either Year 1 or Year 2 of the program were interviewed. Participants were speech-language pathologists, special educators, para-educators, and other related service providers. Using a grounded theory approach (Glaser & Strauss, 1967 ) to data analysis, open, axial, and selective coding procedures were followed. Results Three themes emerged from the data analysis and included engagement as the goal, role as a communication partner, and importance of collaboration. Conclusions Findings supported the notion that educators see the value of an integrative approach to service delivery, supporting students' social communication and engagement across the school day but also recognizing the challenges they face in making this a reality.

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