scholarly journals The power of low-resolution spectroscopy: On the spectral classification of planet candidates in the ground-based CoRoT follow-up

2015 ◽  
Vol 336 (2) ◽  
pp. 134-144 ◽  
Author(s):  
M. Ammler-von Eiff ◽  
D. Sebastian ◽  
E. W. Guenther ◽  
B. Stecklum ◽  
J. Cabrera
Keyword(s):  
Spectral Classification ◽  
Low Resolution

scholarly journals The Explosive Universe with Gaia

2013 ◽  
Vol 9 (S298) ◽  
pp. 446-446
Author(s):  
Łukasz Wyrzykowski ◽  
Simon T. Hodgkin ◽  
Nadejda Blagorodnova ◽  
Vasily Belokurov
Keyword(s):  
Matter Content ◽  
Low Resolution ◽  
Mass Measurements ◽  
Tidal Disruption ◽  
The Galaxy ◽  
Transient Sources ◽  
Cross Matching ◽  
Unique Mass

AbstractThe Gaia mission will observe the entire sky for 5 years providing ultra-precise astrometric, photometric and spectroscopic measurements for a billion stars in the Galaxy. Hence, naturally, Gaia becomes an all-sky multi-epoch photometric survey, which will monitor and detect variability with millimag precision as well as new transient sources such as supernovae, novae, microlensing events, tidal disruption events, asteroids, among others.Gaia data-flow allows for quick detections of anomalies within 24-48h after the observation. Such near-real-time survey will be able to detect about 6000 supernovae brighter than 19 mag up to redshifts of Z 0.15. The on-board low-resolution (R 100) spectrograph will allow for early and robust classification of transients and minimise the false-alert rate, even providing the estimates on redshift for supernovae. Gaia will also offer a unique possibility for detecting astrometric shifts in microlensing events, which, combined with Gaia's and ground-based photometry, will provide unique mass measurements of lenses, constrains on the dark matter content in the Milky Way and possible detections of free floating black holes.Alerts from Gaia will be publicly available soon after the detection is verified and tested. First alerts are expected early in 2014 and those will be used for ground-based verification. All facilities are invited to join the verification and the follow-up effort. Alerts will be published on a web page, via Skyalert.org and via emailing list. Each alert will contain coordinates, Gaia light curve and low-resolution spectra, classification and cross-matching results.More information on the Gaia Science Alerts can be found here: http://www.ast.cam.ac.uk/ioa/wikis/gsawgwiki/The full version of the poster is available here: http://www.ast.cam.ac.uk/ioa/wikis/gsawgwiki/images/1/13/GaiaAlertsPosterIAUS298.pdf

scholarly journals Wolf–Rayet stars in M 81 using GTC/OSIRIS: seven new detections, analysis, and classification of the full sample

2020 ◽  
Vol 493 (3) ◽  
pp. 3879-3892
Author(s):  
V M A Gómez-González ◽  
Y D Mayya ◽  
D Rosa-González ◽  
L H Rodríguez-Merino ◽  
J A Toalá ◽  
...  
Keyword(s):  
Massive Star ◽  
Large Magellanic Cloud ◽  
Evolutionary Models ◽  
Spectral Classification ◽  
Entire Sample ◽  
Full Sample ◽  
Evolutionary Path ◽  
Set Up

ABSTRACT We report the detection of seven new Wolf–Rayet (WR) star locations in M 81 using the Multi-Object Spectrograph of the OSIRIS instrument at Gran Telescopio Canarias. These detections are the result of a follow-up of an earlier study using the same instrumental set-up that resulted in the detection of 14 WR locations. We analyse the entire sample of 21 spectra to classify them to one of the known WR sub-types using template spectra of WR stars in the Large Magellanic Cloud (LMC), with similar metallicity to M 81. Taking into consideration the dispersion in the strengths of the bumps for a given WR sub-type, we found that 19 of the 21 locations correspond to individual stars, including all the seven new detections, of sub-types: WNL, WNE, WCE, and the transitional WN/C. None of the detections correspond to WCL or WO types. The positions of these stars in the red bump versus blue bump luminosity diagram agrees well with an evolutionary path according to the Conti scenario. Based on this, we propose this diagram as a straightforward tool for spectral classification of extragalactic WR sources. The detection of individual WR stars in M 81, which is at a distance of 3.6 Mpc, opens up a new environment for testing the massive star evolutionary models.

scholarly journals A Survey of X-ray–Emitting IRAS Galaxies: A New Class of Objects or Hidden AGNs?

1997 ◽  
Vol 159 ◽  
pp. 421-422
Author(s):  
M. Dennefeld
Keyword(s):  
Spectral Resolution ◽  
Cross Correlation ◽  
Unexpected Result ◽  
Frequency Of Occurrence ◽  
Spectral Classification ◽  
X Ray ◽  
New Class ◽  
Sky Survey

A cross-correlation between the IRAS PSC and the ROSAT All-Sky Survey has provided 242 sources detected in both surveys (Boiler et al. 1992). About half of these have redshifts in the literature and a spectral classification. An unexpected result was the discovery of many galaxies with X-ray luminosities up to a few 1043 ergs s−1, yet without Seyfert characteristics in their optical spectra (e.g., Boiler et al. 1993). To investigate this problem further and evaluate the frequency of occurrence of these peculiar objects, a spectroscopic follow-up has been undertaken to:• Determine velocities and luminosities for all the unclassified objects.• Reevaluate the classification of high X-ray luminosity objects previously not recognized as Seyferts. In particular, spectral resolution or coverage and variability are important parameters to consider if one wants to detect faint signs of Seyfert activity.

Note on the spectral classification of carbon stars in the photographic infrared region

1966 ◽  
Vol 24 ◽  
pp. 21-23
Author(s):  
Y. Fujita
Keyword(s):  
Infrared Region ◽  
Spectral Classification ◽  
Carbon Stars

We have investigated the spectrograms (dispersion: 8Å/mm) in the photographic infrared region fromλ7500 toλ9000 of some carbon stars obtained by the coudé spectrograph of the 74-inch reflector attached to the Okayama Astrophysical Observatory. The names of the stars investigated are listed in Table 1.

Die Wirksamkeit eines Frühinterventionsprogramms für Jugendliche mit Computerspiel- und Internetabhängigkeit: Mittelfristige Effekte der PROTECT+ Studie

2020 ◽  
Vol 48 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Carolin Szász-Janocha ◽  
Eva Vonderlin ◽  
Katajun Lindenberg
Keyword(s):  
Internet Use ◽  
Health Problems ◽  
Reliable Change Index ◽  
Gaming Disorder ◽  
Statistical Classification ◽  
Reliable Change ◽  
Classification Of Diseases ◽  
International Statistical Classification

Zusammenfassung. Fragestellung: Das junge Störungsbild der Computerspiel- und Internetabhängigkeit hat in den vergangenen Jahren in der Forschung zunehmend an Aufmerksamkeit gewonnen. Durch die Aufnahme der „Gaming Disorder“ in die ICD-11 (International Statistical Classification of Diseases and Related Health Problems) wurde die Notwendigkeit von evidenzbasierten und wirksamen Interventionen avanciert. PROTECT+ ist ein kognitiv-verhaltenstherapeutisches Gruppentherapieprogramm für Jugendliche mit Symptomen der Computerspiel- und Internetabhängigkeit. Die vorliegende Studie zielt auf die Evaluation der mittelfristigen Effekte nach 4 Monaten ab. Methodik: N = 54 Patientinnen und Patienten im Alter von 9 bis 19 Jahren (M = 13.48; SD = 1.72) nahmen an der Frühinterventionsstudie zwischen April 2016 und Dezember 2017 in Heidelberg teil. Die Symptomschwere wurde zu Beginn, zum Abschluss der Gruppentherapie sowie nach 4 Monaten anhand von standardisierten Diagnostikinstrumenten erfasst. Ergebnisse: Mehrebenenanalysen zeigten eine signifikante Reduktion der Symptomschwere anhand der Computerspielabhängigkeitsskala (CSAS) nach 4 Monaten. Im Selbstbeurteilungsbogen zeigte sich ein kleiner Effekt (d = 0.35), im Elternurteil ein mittlerer Effekt (d = 0.77). Der Reliable Change Index, der anhand der Compulsive Internet Use Scale (CIUS) berechnet wurde, deutete auf eine starke Heterogenität im individuellen Symptomverlauf hin. Die Patientinnen und Patienten bewerteten das Programm zu beiden Follow-Up-Messzeitpunkten mit einer hohen Zufriedenheit. Schlussfolgerungen: Die vorliegende Arbeit stellt international eine der wenigen Studien dar, die eine Reduktion der Symptome von Computerspiel- und Internetabhängigkeit im Jugendalter über 4 Monate belegen konnte.

Ultraviolet Spectral Classification of O and B Stars in the Large Magellanic Cloud

1999 ◽  
Vol 117 (6) ◽  
pp. 2856-2867 ◽  
Author(s):  
Margaret M. Smith Neubig ◽  
Frederick C. Bruhweiler
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Spectral Classification ◽  
B Stars

scholarly journals NIMG-53. GLUTAMATE/GABA RATIO ON MRS IS ELEVATED IN PATIENTS WITH LOWER GRADE GLIOMAS AND SEIZURES

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii159-ii160
Author(s):  
Roberta Rudà ◽  
Riccardo Pascuzzo ◽  
Francesca Mo ◽  
Alessia Pellerino ◽  
Peter B Barker ◽  
...  
Keyword(s):  
Tumor Location ◽  
Resonance Spectroscopy ◽  
Lower Grade ◽  
Lack Of Information ◽  
Baseline Evaluation ◽  
Grade Ii ◽  
Grade Iii

Abstract BACKGROUND There is lack of information on the role of excitatory and inhibitory neurotransmitters in the development of seizures in patients with lower grade gliomas. Increase of glutamate and downregulation of GABA have been suggested in preclinical models and human surgical samples to be associated with brain tumor-related epilepsy. MATERIAL AND METHODS We prospectively investigated with the use of magnetic resonance spectroscopy (MRS) the differences in the ratio of metabolites (glutamate/GABA, glutamate/creatine and GABA/creatine) in the peritumoral areas between patients with or without seizures in a series of lower grade gliomas. Tumors were classified according to WHO Classification of 2016 as follows:11 grade II IDH mutated and 1p/19q codeleted; 3 grade III IDH mutated and 1p/19q codeleted; 6 grade II IDH mutated and 1p/19q intact; 1 grade III IDH mutated and 1p/19q intact; 1 grade II IDH wild-type. Patients received surgery alone or followed by temozolomide chemotherapy according to the presence of risk factors. RESULTS At baseline evaluation, maximum glutamate/GABA values were significantly higher (p=0.023) in the peritumoral area of patients with seizures (1.008 ± 0.368) with respect to those without seizures (0.691 ± 0.170). No other metabolites ratio showed significant differences between the two groups. Similar results were obtained when analyzing the metabolites ratio in the examinations during the follow-up. In the cohort of patients with seizures (n.14) variations of metabolite ratios were not associated with tumor location, 1p/19q codeletion, use of AEDs, concomitant chemotherapy or seizure characteristics (type, duration, frequency). CONCLUSIONS The study is ongoing with the aim of analyzing further the correlations between ratio of metabolites and status of the tumor (stable vs progressive).

MRI analysis and surgical treatment of Wassel Type IV duplicated thumbs

2021 ◽  
pp. 175319342098321
Author(s):  
Anyuan Wang ◽  
Jian Ding ◽  
Long Wang ◽  
Tinggang Chu ◽  
Zhipeng Wu ◽  
...  
Keyword(s):  
Type A ◽  
Surgical Reconstruction ◽  
Mri Findings ◽  
Level Of Evidence ◽  
Type D ◽  
Type Iv ◽  
Secondary Operations ◽  
Type C

We present the MRI findings for 39 Wassel Type IV duplicated thumbs in 38 patients. We found that MRI revealed the morphology of the cartilaginous connection between the thumb anlages and the location of the deviation corresponding to the classification of Horii, which allowed precise preoperative planning of corrective osteotomies. All 39 thumbs were available for follow-up after surgical reconstruction at a mean of 29 months (range 25 to 39). Four out of nine Horii Type A cases and all 12 Type B, as well as the six Type C and the six Type D cases, achieved good results according to the Tada scoring system. Five Type A cases achieved fair results with residual stiffness of the interphalangeal joint. No secondary operations were needed. We conclude that MRI proved useful in subclassifying Wassel Type IV duplicated thumbs and may aid in planning the osteotomies needed for their reconstruction. Level of evidence: IV

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