Spin clusters inside four young asteroid groups

2020 ◽  
Vol 493 (2) ◽  
pp. 2556-2567
Author(s):  
V Carruba ◽  
L G M Ramos ◽  
F Spoto
Keyword(s):  
Numerical Simulations ◽  
Transition Region ◽  
Semimajor Axis ◽  
Family Members ◽  
Proper Elements ◽  
The Family ◽  
Induced Fission ◽  
Spin Clusters ◽  
Spin Pairs ◽  
Asteroid Families

ABSTRACT Asteroid groups may either form because of collisions or because of spin induced fission. Recently it has been shown that young spin clusters tend to form more frequently in young collisional families than in older groups. Here, we study the occurrence of spin clusters inside four very recently identified asteroid groups: the (525) Adelaide, (2258) Viipuri, (6142) Tantawi, and (18429) (1994 AO1) groups. Using combinations of techniques based on backward numerical simulations, we identify four spin pairs among the family members. All groups have fractions of observed spin clusters well above 5 per cent, so confirming an observed trend for other young asteroid groups. The (2258) Viipuri and (18429) (1994 AO1) groups are compatible with an origin as a spin clusters themselves, and could be other occurrences of cascade spin clusters, as recently detected in other asteroid groups. Finally, the separation between collisional asteroid families and spin clusters in domains of dispersion of proper semimajor axis, σa, versus age seems to be more complex than previously thought. While spin clusters tend to be much more compact in proper elements than collisional families, there appears to be a transition region in σa where both the groups be found.

scholarly journals What we know about Families of Asteroids

1989 ◽  
Vol 8 ◽  
pp. 273-279
Author(s):  
V. Zappala’
Keyword(s):  
Family Members ◽  
Parent Body ◽  
Classification Methods ◽  
Hypervelocity Impacts ◽  
Mass Distributions ◽  
Proper Elements ◽  
The Family ◽  
Families Of Asteroids ◽  
Asteroid Families ◽  
Degree Of Fragmentation

AbstractAsteroid families are considered for the most to represent fragments of collisional breakup of precursor bodies. If true, this offers the unique possibility to examine the interiors of large bodies and to study the processes of collision on a scale much larger than can be done in laboratory. Indeed, the general features of the mass distributions and of the ejection velocities of the family members can be interpreted in terms of collisional disruption of a parent body followed by self-gravitational reaccumulation on the largest remnant. However, several problems remain open: a) the degree of fragmentation in real families is generally lower than that observed for experimental targets; b) the relative velocities computed including also proper eccentricity and inclination differences are higher by about a factor 4 than those derived from semiaxes differences only; c) only very few of the presently proposed families have distributions of inferred mineralogies consistent with cosmochemistry. Further studies are needed, including better proper elements computation, classification methods, and new investigations on the physics of hypervelocity impacts.

scholarly journals Extended Families in the Main Belt and in the Trojan Swarms

2005 ◽  
Vol 13 ◽  
pp. 758-758 ◽  
Author(s):  
Zoran Knezevic ◽  
Andrea Milani
Keyword(s):  
Hubble Space Telescope ◽  
Family Members ◽  
Mean Motion Resonances ◽  
Size Dependent ◽  
Proper Elements ◽  
Chaotic Diffusion ◽  
Large Spread ◽  
The Family ◽  
Long Time ◽  
Asteroid Families

The availability of highly accurate synthetic proper elements for a large number of asteroids made possible detailed studies of the structure of asteroid families. The entire region of the Vesta family is dominated by bodies with D < 7 km. The large spread of family members appears to be primarily due to Yarkovsky mobility, a strongly size-dependent. The proper elements of the asteroids the region (except close to mean motion resonances) are stable over very long time spans; thus chaotic diffusion could not play a significant role. The total volume of the family members with diameter less than 7 km amounts approximately to 6 x 104 cubic km, the volume of a crater with 100 km diameter and average depth 7 km. If the albedo feature, visible in the Hubble Space Telescope images, is really a crater its volume could be even larger. Thanks to the recently computed catalogs of proper elements for 1167 trojans, there are now confirmed dynamical families in the trojan swarms. This allows to begin to study the collisional evolution with constraints from observations.

scholarly journals Asteroid Families

1994 ◽  
Vol 160 ◽  
pp. 395-414 ◽  
Author(s):  
Vincenzo Zappalà ◽  
Alberto Cellino
Keyword(s):  
Numerical Simulations ◽  
Excellent Agreement ◽  
Present Review ◽  
The Family ◽  
Suitable Technique ◽  
Asteroid Families ◽  
Collisional Evolution

In spite of their widely recognized importance in the framework of the modern understanding of the asteroidal population and its collisional evolution, asteroid dynamical families have long been a puzzling subject of research, due to the disagreement among the family lists published by different authors. In the present review, the definition and meaning of asteroid families are critically discussed, as well as the various problems which have to be faced by any suitable technique of family identification. In this respect, major improvements have been achieved during the last few years. The most recent family searches show an excellent agreement both in the number of reliably identified families, and in their members. Moreover, the overall performances of the most recent techniques of family identification have been tested by means of numerical simulations, with encouraging results. For these reasons, we believe that we are presently at the beginning of an era in which detailed physical studies of families can be attempted, and observational campaigns can be planned on the basis of solid evidence, like in the case of the recent spectacular results obtained for the family associated to the large asteroid 4 Vesta.

scholarly journals Secular evolution of asteroid families: the role of Ceres

2015 ◽  
Vol 10 (S318) ◽  
pp. 46-54 ◽  
Author(s):  
Bojan Novaković ◽  
Georgios Tsirvoulis ◽  
Stefano Marò ◽  
Vladimir Đošović ◽  
Clara Maurel
Keyword(s):  
Numerical Simulations ◽  
Main Belt ◽  
Secular Resonance ◽  
Secular Evolution ◽  
Secular Dynamics ◽  
Proper Elements ◽  
Post Impact ◽  
Actual Shape ◽  
Asteroid Families

AbstractWe consider the role of the dwarf planet Ceres on the secular dynamics of the asteroid main belt. Specifically, we examine the post impact evolution of asteroid families due to the interaction of their members with the linear nodal secular resonance with Ceres. First, we find the location of this resonance and identify which asteroid families are crossed by its path. Next, we summarize our results for three asteroid families, namely (1726) Hoffmeister, (1128) Astrid and (1521) Seinajoki which have irregular distributions of their members in the proper elements space, indicative of the effect of the resonance. We confirm this by performing a set of numerical simulations, showcasing that the perturbing action of Ceres through its linear nodal secular resonance is essential to reproduce the actual shape of the families.

scholarly journals Analysis of the Karma asteroid family

2020 ◽  
Vol 501 (1) ◽  
pp. 356-366
Author(s):  
Debora Pavela ◽  
Bojan Novaković ◽  
Valerio Carruba ◽  
Viktor Radović
Keyword(s):  
Numerical Simulations ◽  
Family Members ◽  
Dynamical Evolution ◽  
Absolute Magnitude ◽  
Parent Body ◽  
Outer Edge ◽  
Middle Part ◽  
Near Earth Space ◽  
The Family ◽  
Original Family

ABSTRACT The Karma asteroid family is a group of primitive asteroids in the middle part of the main belt, just at the outer edge of the 3J:1A mean-motion resonance. We obtained the list of the family members with 317 asteroids, and estimated that it was formed by the catastrophic disruption of a parent body that was between 34 and 41 km in diameter. Based on the V-shape method, age of the Karma family is estimated to be about 137 Myr. A detailed dynamical map of the region combined with numerical simulations allowed us to reconstruct the long-term dynamical evolution of the family, and to identify the mechanisms responsible for this evolution. The numerical simulations successfully reproduced the main features in the orbital distribution of the family members but also showed that some regions of the Karma family could be missing. A more detailed analysis revealed that these regions likely consist of very dark objects, fainter than absolute magnitude H = 17, that have not yet been detected. Based on the obtained results, we concluded that magnitude–frequency distribution of family members up to H = 16 mag is neither affected by dynamical erosion nor observational incompleteness, and therefore represents the result of collisional grinding of the original family population. Finally, we found that the Karma family have been supplying some asteroids to the near-Earth region via the 3J:1A resonance. Currently, there should about 10 family members larger than 1 km in diameter, orbiting in the near-Earth space.

scholarly journals Excluding interlopers from asteroid families

2014 ◽  
Vol 9 (S310) ◽  
pp. 174-175
Author(s):  
Viktor Radović ◽  
Bojan Novaković
Keyword(s):  
Family Members ◽  
New Approach ◽  
The Family ◽  
Asteroid Families

AbstractTo study an asteroid family it is crucial to determine reliably the list of its members, i.e. to reduce the number of interlopers as much as possible. However, as the number of known asteroids increases fast it becomes more and more difficult to obtain robust list of members of an asteroid family. To cope with these challenges we are proposing a new approach that may help to significantly reduce presence of interlopers among the family members.

POLA PENDIDIKAN AGAMA DALAM KELUARGA JAMA’AH TABLIGH DI DESA BOLANG KECAMATAN DAYEUHLUHUR KABUPATEN CILACAP

2019 ◽  
Vol 20 (2) ◽  
pp. 283-298
Author(s):  
Kholid Mawardi ◽  
Cucu Nurzakiyah
Keyword(s):  
Religious Education ◽  
Adult Children ◽  
Daily Activity ◽  
Family Members ◽  
Special Study ◽  
Children's Education ◽  
The Family ◽  
Children’S Education ◽  
The Village

The results of the study found that the responsibility of religious education of children in the family of Tablighi Jama'ah differed in terms of several conditions, namely first, when parents were not going to khuruj where both parents were responsible for children's education; secondly, when the father goes khuruj, then the mother is responsible for everything including children's education; third, when both parents go khuruj, then the responsibility of the child is left to other family members such as grandparents or their first adult children; and fourth, when the child goes to khuruj, where parents are responsible for children's religious education both mother and father. The pattern of the religious education in the Tablighi Jama'ah family in the village of Bolang is formed from several similarities held in the implementation of religious education, one of which is the daily activity that is carried out by the Tablighi Jama'at family. Al-Qur'an becomes one of the material given to children in the ta'lim. Children are taught how to read the Qur'an and memorize short letters such as Surat al-Falaq, al-Ikhlas, and so on. In addition to al-Qur'an, in this ta'lim there is a special study in the Tablighi Jama'ah, which is reading the book of fadhilah ‘amal, and the last is mudzakarah six characteristics.

Information Practices of Baby Boomers as Caregivers

2013 ◽  
Author(s):  
Khuan Seow ◽  
Nadia Caidi
Keyword(s):  
Social Policy ◽  
Baby Boomers ◽  
Information Needs ◽  
Family Members ◽  
Age Groups ◽  
Maladie D’Alzheimer ◽  
Policy Makers ◽  
Age Related ◽  
The Family ◽  
Growing Age

Canada has an aging population with the fastest growing age groups (80 and 45-64 years old) vulnerable to age-related diseases such as Alzheimer’s disease. Caregiving responsibilities often fall to the family members of the afflicted without much attention and consideration being placed on the information needs of these caregivers. We call for a better understanding of these caregivers' information needs and uses by social policy makers as well as information providers.La population du Canada a tendance à vieillir considérablement, avec la hausse la plus rapide dans les groupes d’âge (80 et 45 à 64 ans). Les personnes âges sont très vulnérables à toute sorte de maladies, telles que la maladie d’Alzheimer. La responsabilité revient souvent aux membres de la famille qui doivent prendre soin des personnes atteintes de cette maladie. Or, nous ne connaissons que peu de chose sur les besoins en information des personnes qui prennent soin de ces malades de l’Alzheimer : qui sont-ils ? Quelles sont leurs sources... 

Pengaruh Penyuluhan Terhadap Respon Psikososial Keluarga Pasien Yang Dirawat Di Ruang Icu Rsud Dr.Sosodoro Djatikoesumo Bojonegoro

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Maslichah Maslichah ◽  
Bayu Akbar Khayudin ◽  
Ikha Ardianti
Keyword(s):  
Health Workers ◽  
Family Members ◽  
T Test ◽  
Family Counseling ◽  
Test Design ◽  
Significance Level ◽  
Paired Sample ◽  
The Family ◽  
Post Test ◽  
Psychosocial Responses

ABSTRAK Pasien yang dirawat di ICU pada umumnya mengalami sakit kritis biasanya hal ini akan menimbulkan bebagai  respons psikososial  dari anggota keluarganya. Respons ini dapat berupa respons positif maupun respons negatif. Salah satu cara agar respons psikososial menjadi positif yaitu memberikan penyuluhan kepada keluarga pasien agar ada peningkatan kognisi dan emosi. Desain penelitian ini menggunakan metode “Pre-Experiment”, dengan rancangan “One group pra-post test design”. Dengan populasi semua keluarga yang anggota keluarganya dirawat di Ruang ICU RSUD.dr.Sosodoro Djatikoesumo. Sampel diambil dengan proses Total Sampling. Variabel independen  yaitupenyuluhan keluarga pasien ICU, dan variabel dependen adalah respon psikososial keluarga pasien. Pengumpulan data menggunakan kuesioner. hasil penelitian yang dilakukan dengan uji statistik paired sample t-test, pada tingkat signifikansi diperoleh nilai 0,027 0,05 maka Ho ditolak dan H1 diterimaPerawat sebagai tenaga kesehatan yang harus selalu mengembangkan profesionalisme, perlu mengupayakan agar respons psikososial keluarga yang negatif dapat ditekan. Salah satu upayanya yaitu adalah memberikan penyuluhan kepada keluarga. Dalam penyuluhan akan diberikan: komunikasi, informasi, edukasi dan support. Kata Kunci : Penyuluhan, Respon Psikososial Keluarga  ABSTRACT Patients admitted to the ICU in general suffer from a critical illness usually this will lead to the kinds of psychosocial responses of family members. This response can be either a positive response or a negative response. One way to be positive psychosocial responses that provide counseling to the patient's family that there was an increase in cognition and emotion.This study design using the "Pre-Experiment", the draft "One group pre-post test design". With a population of all the families who have family members admitted to the ICU RSUD.dr.Sosodoro Djatikoesumo. Samples were taken with total sampling process. Independent variables, family counseling ICU patients, and the dependent variable is the family of the patient's psychosocial response. Collecting data using questionnaires. results of research conducted by the statistical test paired sample t-test, at a significance level obtained value 0,027 0,05 hence Ho refused and H1 accepted.Nurses as health workers must always develop professionalism, needs to strive for psychosocial response can be suppressed negative family. One of the efforts that are giving counseling to the family. In the extension will be granted: communication, information, education and support. Keywords: Counseling, Family Psychosocial Response

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