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2021 ◽  
Vol 923 (2) ◽  
pp. 155
Author(s):  
Rafael Martín-Doménech ◽  
Jennifer B. Bergner ◽  
Karin I. Öberg ◽  
John Carpenter ◽  
Charles J. Law ◽  
...  

Abstract We report the detection of more than 120 emission lines corresponding to eight complex organic molecules (COMs; CH3OH, CH3CH2OH, CH3OCH3, CH3OCHO, CH3COCH3, NH2CHO, CH2DCN, and CH3CH2CN) and three isotopologues (CH2DOH, 13CH3CN, and CH3C15N) toward the western component of the Ser-emb 11 binary young stellar object using observations with the Atacama Large Millimeter/submillimeter Array at ∼1 mm. The complex organic emission was unresolved with a ∼0.″5 beam (∼220 au) in a compact region around the central protostar, and a population diagram analysis revealed excitation temperatures above 100 K for all COMs, indicating the presence of a hot corino. The estimated column densities were in the range of 1017−1018 cm−2 for the O-bearing COMs, and three orders of magnitude lower for the N-bearing species. We also report the detection of H2CO and CH3OH emission in a nearby millimeter source that had not been previously cataloged. Ser-emb 11 is classified in the literature as a Class I source near the Class 0/I cutoff. The estimated COM relative abundances in Ser-emb 11 W and the other three Class I hot corino sources reported in the literature are consistent with those of Class 0 hot corinos, suggesting a continuity in the chemical composition of hot corinos during protostellar evolution.


2021 ◽  
Author(s):  
Sonja Murto ◽  
Rodrigo Caballero ◽  
Gunilla Svensson ◽  
Lukas Papritz

<p>Atmospheric blocking can influence Arctic weather by diverting the mean westerly flow polewards, bringing warm, moist air to high latitudes. Recent studies have shown that diabatic heating processes in the ascending warm conveyor belt branch of extratropical cyclones are relevant to blocking dynamics. This leads to the question of the extent to which diabatic heating associated with mid-latitude cyclones may influence high-latitude blocking and drive Arctic warm events. In this study we investigate the dynamics behind 50 extreme warm events of wintertime high Arctic surface temperature anomalies. We find that 30 of these events are associated with “Ural” blocking, featuring negative upper-level PV anomalies over central Siberia north of the Ural Mountains. Lagrangian back-trajectory calculations show that almost 70% of the air parcels making up these negative PV anomalies experience lifting and diabatic heating (average 14,7 K) in the 9-days prior to blocking. Further, 43,4 % of the heated trajectories undergo maximum heating and lifting in a compact region of the midlatitude North Atlantic, temporally taking place between 6 and 2.5 days before arriving in the blocking region. These trajectories mainly reside in the subtropics before being advected into the lifting region. We also find anomalously high cyclonic activity (on average 3,9 cyclones within a 3,5-day window around the time of maximum lifting) within a sector northwest of the main lifting domain. This study highlights the importance of the interaction between mid-latitude cyclones and Eurasian blocking as driver for Arctic warm extremes.</p>


2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Seung-Yeal Ha ◽  
Myeongju Kang ◽  
Bora Moon

<p style='text-indent:20px;'>We study a uniform-in-time continuum limit of the lattice Winfree model(LWM) and its asymptotic dynamics which depends on system functions such as natural frequency function and coupling strength function. The continuum Winfree model(CWM) is an integro-differential equation for the temporal evolution of Winfree phase field. The LWM describes synchronous behavior of weakly coupled Winfree oscillators on a lattice lying in a compact region. For bounded measurable initial phase field, we establish a global well-posedness of classical solutions to the CWM under suitable assumptions on coupling function, and we also show that a classical solution to the CWM can be obtained as a <inline-formula><tex-math id="M1">\begin{document}$ L^1 $\end{document}</tex-math></inline-formula>-limit of a sequence of lattice solutions. Moreover, in the presence of frustration effect, we show that stationary states and bump states can emerge from some admissible class of initial data in a large and intermediate coupling regimes, respectively. We also provide several numerical examples and compare them with analytical results.</p>


Author(s):  
M. A. Gorbachev ◽  
◽  
M. S. Butuzova ◽  
S. V. Nazarov ◽  
◽  
...  

The optical radiation of the blazar S5 0716+714 is formed within its ultrarelativistic jet in a compact region located near the true origin of the jet. Assuming that the variability is formed only by changing the relativistic radiation amplification coefficient (Doppler factor) for some part of the emitting region and that the spectrum of the emitting region, characterized by a power law at the observed frequencies, has a turn-over at lower frequencies, caused by synchrotron self-absorption, we analyze the archival data of the Crimean Astrophysical Observatory of B-, V-, R-, I-photometry of the blazar S5 0716+714 from 2002 to 2019. An explanation for the observed change in the color index during the blazar S5 0716+714 variability without changes in the physical parameters of the source was obtained.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Adam N Berman ◽  
David W Biery ◽  
Avinainder Singh ◽  
Jonggyu Baek ◽  
Wanda Y Wu ◽  
...  

Introduction: Living in a disadvantaged neighborhood is associated with developing cardiovascular disease and poor health outcomes. We hypothesized that socioeconomic disadvantage - as measured by neighborhood level factors - is associated with cardiovascular (CV) mortality for patients who experienced a myocardial infarction (MI) at a young age. Methods: Retrospective cohort study of patients with a first MI at age <50 years treated at two medical centers from 2000 - 2016. Each patient’s home address was mapped to their census block group (CBG), a geographically compact region containing ~ 600 to 3000 people. For each CBG, we obtained the Neighborhood Stress Score (NSS) - a standardized score based on 7 census variables that Massachusetts Medicaid uses to measure socioeconomic stress. Patients were assigned an NSS score based on their CBG and stratified into tertiles of risk. Higher scores indicate greater socioeconomic disadvantage. We used Cox proportional hazards modeling to evaluate the association of NSS with CV mortality. Results: Of 2097 patients (median age 44; 19% female), addresses were available for 96%. The median NSS score was -0.31, with scores ranging from -1.11 to 5.33. Higher NSS scores were associated with public insurance, hypertension, diabetes, smoking cigarettes, and illicit drug use. Over a median follow-up of 11 years, 12.7% of individuals in the top tertile died versus 7.5% in the bottom tertile, p=0.002. After adjusting for age, sex, race, diabetes, hypertension, dyslipidemia, creatinine, tobacco smoking, use of alcohol or illicit drugs, cardiac catheterization, and statin or aspirin at discharge, each 1-point increase in NSS was associated with a 25% increase in CV mortality (adjusted HR = 1.25, [95% CI 1.01 - 1.55], p=0.045). Conclusion: Among patients experiencing an MI at a young age, socioeconomic disadvantage was associated with higher CV mortality. Our data suggest that neighborhood factors have an important effect on post-MI survival.


2020 ◽  
Vol 643 ◽  
pp. A56
Author(s):  
◽  
A. Jiménez-Rosales ◽  
J. Dexter ◽  
F. Widmann ◽  
M. Bauböck ◽  
...  

We study the time-variable linear polarisation of Sgr A* during a bright near-infrared flare observed with the GRAVITY instrument on July 28, 2018. Motivated by the time evolution of both the observed astrometric and polarimetric signatures, we interpret the data in terms of the polarised emission of a compact region (“hotspot”) orbiting a black hole in a fixed, background magnetic field geometry. We calculated a grid of general relativistic ray-tracing models, created mock observations by simulating the instrumental response, and compared predicted polarimetric quantities directly to the measurements. We take into account an improved instrument calibration that now includes the instrument’s response as a function of time, and we explore a variety of idealised magnetic field configurations. We find that the linear polarisation angle rotates during the flare, which is consistent with previous results. The hotspot model can explain the observed evolution of the linear polarisation. In order to match the astrometric period of this flare, the near horizon magnetic field is required to have a significant poloidal component, which is associated with strong and dynamically important fields. The observed linear polarisation fraction of ≃30% is smaller than the one predicted by our model (≃50%). The emission is likely beam depolarised, indicating that the flaring emission region resolves the magnetic field structure close to the black hole.


2020 ◽  
Vol 636 ◽  
pp. A108 ◽  
Author(s):  
J. Bouvier ◽  
K. Perraut ◽  
J.-B. Le Bouquin ◽  
G. Duvert ◽  
C. Dougados ◽  
...  

Context. Young stellar objects are thought to accrete material from their circumstellar disks through their strong stellar magnetospheres. Aims. We aim to directly probe the magnetospheric accretion region on a scale of a few 0.01 au in a young stellar system using long-baseline optical interferometry. Methods. We observed the pre-transitional disk system DoAr 44 with VLTI/GRAVITY on two consecutive nights in the K-band. We computed interferometric visibilities and phases in the continuum and in the Brγ line in order to constrain the extent and geometry of the emitting regions. Results. We resolve the continuum emission of the inner dusty disk and measure a half-flux radius of 0.14 au. We derive the inclination and position angle of the inner disk, which provides direct evidence that the inner and outer disks are misaligned in this pre-transitional system. This may account for the shadows previously detected in the outer disk. We show that Brγ emission arises from an even more compact region than the inner disk, with an upper limit of 0.047 au (~5 R⋆). Differential phase measurements between the Brγ line and the continuum allow us to measure the astrometric displacement of the Brγ line-emitting region relative to the continuum on a scale of a few tens of microarcsec, corresponding to a fraction of the stellar radius. Conclusions. Our results can be accounted for by a simple geometric model where the Brγ line emission arises from a compact region interior to the inner disk edge, on a scale of a few stellar radii, fully consistent with the concept of magnetospheric accretion process in low-mass young stellar systems.


2020 ◽  
Vol 635 ◽  
pp. A48 ◽  
Author(s):  
S. Manigand ◽  
J. K. Jørgensen ◽  
H. Calcutt ◽  
H. S. P. Müller ◽  
N. F. W. Ligterink ◽  
...  

Context. Complex organic molecules are detected in many sources in the warm inner regions of envelopes surrounding deeply embedded protostars. Exactly how these species form remains an open question. Aims. This study aims to constrain the formation of complex organic molecules through comparisons of their abundances towards the Class 0 protostellar binary IRAS 16293–2422. Methods. We utilised observations from the ALMA Protostellar Interferometric Line Survey of IRAS 16293–2422. The species identification and the rotational temperature and column density estimation were derived by fitting the extracted spectra towards IRAS 16293–2422 A and IRAS 16293–2422 B with synthetic spectra. The majority of the work in this paper pertains to the analysis of IRAS 16293–2422 A for a comparison with the results from the other binary component, which have already been published. Results. We detect 15 different complex species, as well as 16 isotopologues towards the most luminous companion protostar IRAS 16293–2422 A. Tentative detections of an additional 11 isotopologues are reported. We also searched for and report on the first detections of methoxymethanol (CH3OCH2OH) and trans-ethyl methyl ether (t-C2H5OCH3) towards IRAS 16293–2422 B and the follow-up detection of deuterated isotopologues of acetaldehyde (CH2DCHO and CH3CDO). Twenty-four lines of doubly-deuterated methanol (CHD2OH) are also identified. Conclusions. The comparison between the two protostars of the binary system shows significant differences in abundance for some of the species, which are partially correlated to their spatial distribution. The spatial distribution is consistent with the sublimation temperature of the species; those with higher expected sublimation temperatures are located in the most compact region of the hot corino towards IRAS 16293–2422 A. This spatial differentiation is not resolved in IRAS 16293–2422 B and will require observations at a higher angular resolution. In parallel, the list of identified CHD2OH lines shows the need of accurate spectroscopic data including their line strength.


Author(s):  
S Carniani ◽  
S Gallerani ◽  
L Vallini ◽  
A Pallottini ◽  
M Tazzari ◽  
...  

Abstract We present Atacama Large Millimiter/submillimiter Array (ALMA) observations of eight highly excited CO (${\rm J_{\rm up}}$ >8) lines and continuum emission in two z ∼ 6 quasars: SDSS J231038.88+185519.7 (hereafter J2310), for which CO(8-7), CO(9-8), and CO(17-16) lines have been observed, and ULAS J131911.29+095951.4 (J1319), observed in the CO(14-13), CO(17-16) and CO(19-18) lines. The continuum emission of both quasars arises from a compact region (<0.9 kpc). By assuming a modified black-body law, we estimate dust masses of Log(Mdust/M⊙) = 8.75 ± 0.07 and Log(Mdust/M⊙) = 8.8 ± 0.2 and dust temperatures of Tdust = 76 ± 3 K and $T_{\rm dust}=66^{+15}_{-10}~{\rm K}$, respectively for J2310 and J1319. Only CO(8-7) and CO(9-8) in J2310 are detected, while 3σ upper limits on luminosities are reported for the other lines of both quasars. The CO line luminosities and upper limits measured in J2310 and J1319 are consistent with those observed in local AGN and starburst galaxies, and other z ∼ 6 quasars, except for SDSS J1148+5251 (J1148), the only quasar at z = 6.4 with a previous CO(17-16) line detection. By computing the CO SLEDs normalised to the CO(6-5) line and FIR luminosities for J2310, J1319, and J1149, we conclude that different gas heating mechanisms (X-ray radiation and/or shocks) may explain the different CO luminosities observed in these z ∼ 6 quasar. Future ${\rm J_{\rm up}}$ >8 CO observations will be crucial to understand the processes responsible for molecular gas excitation in luminous high-z quasars.


2019 ◽  
Vol 486 (2) ◽  
pp. 2449-2461 ◽  
Author(s):  
T G Sitnik ◽  
O V Egorov ◽  
T A Lozinskaya ◽  
A V Moiseev ◽  
A M Tatarnikov ◽  
...  

ABSTRACT We present an observational study of small-scale feedback processes operating in the star-forming region located in the wall of the expanding supershell around the Cyg OB1 association. The interstellar gas and dust content and pre-stellar populations in the vicinity of the open star cluster vdB 130 are analysed based on new optical and IR observations performed with the 6-m (3D spectroscopic mapping in the [S ii] doublet) and 2.5-m (optical and NIR images) Russian telescopes along with the archival data of Spitzer and Herschel space telescopes. Analysing ionized gas kinematics and emission spectra, we discovered a compact region with supersonic motions. These motions may be caused either by stellar wind or a bipolar outflow from a protostellar disc. Young stellar objects were identified and classified in the area under study. Two star-forming regions were identified. One of them is a region of ongoing star formation in the head of the molecular cloud observed there and another one is a burst of star formation in the cloud tail.


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