scholarly journals Tomography of the Ie-Re and L-Sigma Planes

Universe ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Mauro D’Onofrio ◽  
Cesare Chiosi
Keyword(s):  
Star Formation ◽  
Velocity Dispersion ◽  
Past History ◽  
Small Range ◽  
Stellar Content ◽  
The Past ◽  
Total Luminosity ◽  
Stellar Velocity ◽  
History Of ◽  
Physical Foundation

We have analyzed the distribution of early-type galaxies (ETGs) in the effective surface intensity vs. effective radius (Ie−Re) plane and in the total luminosity vs. central stellar velocity dispersion (L−σ) diagram, with the aim of studying the physical variables that allow the transformation of one space-parameter into the other. We find that the classical Faber–Jackson relation L=L0σα, in which the parameters L0 and α are confined in a small range of possible values, is incompatible with the distribution observed in the Ie−Re plane. The two distributions become mutually consistent only if luminosity is not considered a pure proxy of mass but a variable tightly dependent on the past history of mass assembling and star formation and on the present evolutionary state of the stellar content of a galaxy. The solution comes by considering the L=L0′σβ law proposed by D’Onofrio et al. in 2020, in which both L0′ and β can vary considerably from galaxy to galaxy. We will also show that the data of the Illustris numerical simulation prove the physical foundation of the L=L0′σβ law and confirm the prediction of the Zone of Exclusion (ZoE) originating from the intersection of the virial law with the L=L0′σβ relation. The ZoE is the region in the Ie−Re and Re−Ms diagrams avoided by real galaxies, and the border of which marks the condition of ‘full’ virial equilibrium with no recent significant merger events and no undergoing star formation.

scholarly journals The historical record of massive star formation in Cygnus

2020 ◽  
Vol 644 ◽  
pp. A62
Author(s):  
F. Comerón ◽  
A. A. Djupvik ◽  
N. Schneider ◽  
A. Pasquali
Keyword(s):  
Star Formation ◽  
Massive Star ◽  
Historical Record ◽  
Star Formation History ◽  
Visible Range ◽  
Stellar Content ◽  
Massive Star Formation ◽  
The Past ◽  
Red Supergiants ◽  
History Of

Context. The Cygnus region, which dominates the local spiral arm of the Galaxy, is one of the nearest complexes of massive star formation, extending over several hundred parsecs. Its massive stellar content, regions of ongoing star formation, and molecular gas have been studied in detail at virtually all wavelengths. However, little is known of the history of the region beyond the past 10 Myr. Aims. We use the correlations between age, mass and luminosity of red supergiants to explore the history of star formation in Cygnus previous to the formation of the present-day associations. The brightness and spectroscopic characteristics of red supergiants make it easy to identify them and build up a virtually complete sample of such stars at the distance of the Cygnus region, thus providing a record of massive star formation extending several tens of Myr into the past, a period inaccessible through the O and early B stars observable at present. Methods. We have made a selection based on the 2MASS colors of a sample of bright, red stars in an area of 84 square degrees covering the whole present extension of the Cygnus association in the Local Arm. We have obtained spectroscopy in the red visible range allowing an accurate, homogeneous spectral classification as well as a reliable separation between supergiants and other cool stars. Our data are complemented with Gaia Data Release 2 astrometric data. Results. We have identified 29 red supergiants in the area, 17 of which had not been previously classified as supergiants. Twenty-four of the 29 most likely belong to the Cygnus region and four of the remaining to the Perseus arm. We have used their derived luminosities and masses to infer the star formation history of the region. Intense massive star formation activity is found to have started approximately 15 Myr ago, and we find evidence for two other episodes, one taking place between 20 and 30 Myr ago and another one having ended approximately 40 Myr ago. There are small but significant differences between the kinematic properties of red supergiants younger or older then 20 Myr, hinting that stars of the older group were formed outside the precursor of the present Cygnus complex, possibly in the Sagittarius-Carina arm.

scholarly journals Galactic evolution and the two-colour diagram

1964 ◽  
Vol 20 ◽  
pp. 37-37
Author(s):  
R. H. Stoy
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Past History ◽  
Photometric Data ◽  
Galactic Evolution ◽  
The Past ◽  
The Galaxy ◽  
History Of ◽  
Present Distribution ◽  
Metal Abundances

Information about the past history of the Galaxy may be obtained from a two-colour diagram, since the present distribution of stars in such a diagram depends on the past rate of star formation and the past metal abundances in the interstellar medium. As an illustration of this, I would like to discuss three diagrams that were recently prepared by Dr. M. E. Dixon from Cape photometric data (Dixon 1963a,b).

Obituary notices of fellows deceased

1877 ◽  
Vol 25 (171-178) ◽  
Keyword(s):  
Past History ◽  
The Past ◽  
The Earth ◽  
History Of ◽  
Reign Of Terror ◽  
Accurate Observation

George Poulett Scrope. It is scarcely possible at the present day to realize the conditions of that intellectual “reign of terror” which prevailed at the commencement of the present century, as the consequence of the unreasoning prejudice and wild alarm excited by the early progress of geological inquiry. At that period, every attempt to explain the past history of the earth by a reference to the causes still in operation upon it was met, not by argument, but by charges of atheism against its propounder; and thus Hutton’s masterly fragment of a ‘Theory of the Earth,’ Playfair’s persuasive‘ Illustrations,’ and Hall’s records of accurate observation and ingenious experiment had come to be inscribed m a social Index Expurgatorius ,and for a while, indeed, might have seemed to be consigned to total oblivion. Equally injurious suspicions were aroused against the geologist who dared to make allusion to the important part which igneous forces have undoubtedly played in the formation of certain rocks; for the authority of Werner had acquired an almost sacred cha­racter; and “ Vulcanists ” and “ Huttonians ” were equally objects of aversion and contempt. To two men who have very recently—and within a few months of one another—passed away from our midst, science is indebted for boldly en­countering and successfully overcoming this storm of prejudice. Hutton and his friends lived a generation too soon ; and thus it was reserved tor Lyell and Scrope to carry out the task which the great Scotch philosopher had failed to accomplish, namely, the removal of geology from the domain of speculation to that of inductive science.

scholarly journals Tingkat Kesiapan Kali Pepe untuk Dikembangakan sebagai Kawasan Wisata Berbasis Sungai di Kota Surakarta

Arsitektura ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 67
Author(s):  
Nurul Widowati ◽  
Winny Astuti ◽  
Murtanti Jani Rahayu
Keyword(s):  
Quantitative Research ◽  
Past History ◽  
River Flooding ◽  
Know How ◽  
The Past ◽  
Institutional Infrastructure ◽  
Strategic Location ◽  
Readiness Level ◽  
History Of ◽  
The Government

<div><p><em>Surakarta is a city that has the potential of the river. But in the process, these rivers suffered environmental degradation as a function instead of the banks into slums and squatter, and functions of rivers that serve as places of waste disposal. Government’s city of Surakarta has done various setup area of the river. One of the targeted structuring Pepe-River is often known by the name Kali Pepe. Kali Pepe is the river which has the most strategic location because it divides the centre of city and the river has a past history of Surakarta. Kali Pepe is the witness of history where culture and trade activities in the rapidly growing city of Surakarta in the past with the ecological function and physical function as transportation trade.Setuping Kali Pepe, according to the Mayor of Surakarta, is directed to serve as recreation/tourism area. Since the Surakarta Mayor initiated the year 2015 that Kali Pepe as a tourist area. The initiated moves the government and society in order to more actively participate in developing the area into a tourist area. This research would like to know how the readiness level of the Kali Pepe area to be developed as a tourist area-based streams. The components of preparedness were seen from aspect of attractions or natural tourist attraction, artificial attractions, acessesiblity, institutional, infrastructure supporting tourism, and the behavior of the flooding of the river. This research is quantitative research in methods of scoring analysis. The result of this research has shown that Kali Pepe less readiness to be developed as a tourist area-based stream. Aspects of accessibility and infrastructure supporting tourism were an aspect which has a readiness. But for this aspect of the attraction, institutional and river flooding behavior is still in the stage of less readiness.</em></p><p> </p><p><strong><em>Keywords:</em></strong><em> readiness, tourist areas, river tours</em></p></div>

scholarly journals CAGAR BUDAYA SANG PENUTUR MASA SILAM CULTURAL HERITAGE THE TELLER OF THE PAST

Kebudayaan ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 27-42
Author(s):  
I Made Sutaba
Keyword(s):  
Cultural Heritage ◽  
Past History ◽  
Literature Study ◽  
The Past ◽  
Past Life ◽  
History Of ◽  
Research Goal ◽  
The Many ◽  
Religious Aspects ◽  
Typology Analysis

Archaeological researches in Indonesia have discovered a number of various historical and archaeological artifacts that belong to cultural heritage. As historical evidences, this cultural heritage is an important source of the plural information and messages of the past life of our society. It is remarkable that this cultural heritage has some problems for example problem of typology, function, meanings, and the other for the society. Studying the problems, it is interesting to do research on its function as a teller of the past history that contained various aspects of the life of our society that not yet studied until today. By learning the problems, this research goal is to find the answer of the problems. To reach this goal, we do this research gradually by collecting data through literature study and field observation along with interviews. The next step is analysis carried out through methods of typology analysis, contextual, functional analysis, ethno archaeological and ethno historical approach. Finally the result showed that the function of our cultural heritage is as teller of the many-sided aspects of the past history of our artifacts such as technological aspects, social, and religious aspects but it is impossible to get full completed information due to some reasons. Keywords: archaeological and historical artifacts, cultural heritages, teller of the past.  AbstrakPenyelidikan arkeologi di Indonesia sudah berhasil menemukan artefak sejarah dan arkeologi yang beraneka ragam, yang tergolong sebagai warisan budaya. Sebagai bukti-bukti sejarah, warisan budaya ini adalah sumber informasi dan pesan-pesan kehidupan masyarakat masa lalu yang bersifat pluralistik. Menarik perhatian, bahwa warisan budaya ini mempunyai permasalahan yaitu, permasalahan tipologi, fungsi dan makna dalam kehidupan masyarakat. Mempelajari masalah ini, sangat menarik untuk melakukan penelitian mengenai fungsinya sebagai penutur sejarah masa silam, yang mengandung aneka ragam, aspek kehidupan masyarakat, yang belum dikaji sampai sekarang. Dengan mencermati permasalahan ini, maka tujuan penelitian ini, adalah untuk meneliti permasalahan tadi. Untuk mencapai tujuan ini, penulis melakukan penelitian secara bertahap melalui pengumpulan data dengan metode kajian pustaka dan observasi lapangan yang disertai dengan wawancara. Langkah selanjutnya, adalah melakukan analisis dengan analisis tipologi, kontekstual, analisis fungsional, pendekatan etnoarkeologi dan etnohistori. Hasil penelitian ini menunjukkan bahwa cagar budaya itu berfungsi sebagai penutur kehidupan masa silam yang mengandung aspek yang bersfiat jamak, adalah aspek teknologi, sosial dan religi, tetapi tidak mungkin untuk mendapat informasi yang lengkap karena berbagai faktor.Kata kunci: peninggalan sejarah dan purbakala, warisan budaya, penutur masa silam.

scholarly journals Predictors of proximity to others in colony housed shelter cats (Felis silvestris catus)

2016 ◽  
pp. 24 ◽  
Author(s):  
Malini Suchak ◽  
Michael Piombino ◽  
Kalina Bracco
Keyword(s):  
Past History ◽  
Individual Variability ◽  
Felis Silvestris Catus ◽  
Future Studies ◽  
The Past ◽  
Close Proximity ◽  
History Of ◽  
Adult Cats ◽  
Stress Behaviors ◽  
High Degree

Colony housing of cats allows shelters to maximize the number of cats housed in limited space. Most research on colony-housed cats examines stress in relation to group size or enclosure size.  While this is important for evaluating welfare, it is equally important to understand how cats are interacting socially in these colonies. We observed 259 adult cats housed in groups of two to eight individuals. Scan samples were used to assess how frequently individual cats were in close proximity to other cats. These data were used to measure individual differences in sociability and patterns of proximity to certain partners. We used information about the past history of the cat, which was collected upon admission to the shelter to identify predictors of time spent in proximity. There was a high degree of inter-individual variability in sociability. Strays tended to spend less time in proximity to other cats, and this effect was most pronounced in females.However, none of the information collected upon admission predicted patterns of proximity to certain partners, or which cats spent time in association witheach other. Future studies should explore the implications of differences in sociability by associating observations of social behavior and stress behaviors.

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