Nobeyama Radio ObservatoryNAOJ
GREX-PLUS (Galaxy Reionization EXplorer and PLanetary Universe Spectrometer) is a mission candidate for a JAXA's strategic L-class mission to be launched in the 2030s. Its primary sciences are two-fold: galaxy formation and evolution and planetary system formation and evolution. The GREX-PLUS spacecraft will carry a 1.2 m primary mirror aperture telescope cooled down to 50 K. The two science instruments will be onboard: a wide-field camera in the 2-8 μ\mum wavelength band and a high resolution spectrometer with a wavelength resolution of 30,000 in the 10-18 μ\mum band. The GREX-PLUS wide-field camera aims to detect the first generation of galaxies at redshift z>15z>15. The GREX-PLUS high resolution spectrometer aims to identify the location of the water ``snow line'' in proto-planetary disks. Both instruments will provide unique data sets for a broad range of scientific topics including galaxy mass assembly, origin of supermassive blackholes, infrared background radiation, molecular spectroscopy in the interstellar medium, transit spectroscopy for exoplanet atmosphere, planetary atmosphere in the Solar system, and so on.
In this paper, we investigate the impact of higher-order distortions on the precise measurement of weak gravitational lensing shear and flexion. We begin by defining generalized higher-order distortions and outlining methods for measuring them. Then, using several lens models, we examine how these distortions affect shear and flexion measurements. Our results show that neglecting higher-order distortions can introduce systematic errors of a few percent in both shear and flexion measurements, indicating that these effects cannot be ignored. Although the strength of these errors depends on factors such as lensing strength and the size of background sources, we demonstrate that simultaneous measurement of higher-order distortions can reduce the systematic errors to below 1% in most cases.
Complex organic molecules (COMs) in starless cores provide critical insights into the early stages of star formation and prebiotic chemistry. We present a chemical survey of 16 starless cores (including five prestellar cores) in the Orion A and B molecular clouds, targeting CH3OH, N2H+, CCS, and c-C3HD, using the Atacama Compact Array (ACA) and the Yebes 40-m telescope. CH3OH was detected toward all targets, confirming its ubiquity in starless cores, consistent with previous surveys in Taurus and Perseus. ACA imaging shows that CH3OH, CCS, and c-C3HD generally trace the outer layers of the dense cores outlined by N2H+, each exhibiting distinct spatial distributions. Meanwhile, Comparison with Yebes data reveals an extended, flattened CH3OH component. CCS and c-C3HD tend to be detected or non-detected together across cores, while cores near dust-rich regions on a large scale often lack both, suggesting environmental influences linked to the interstellar radiation field. Within individual cores, CCS typically resides in an outer layer relative to c-C3HD. Our findings underscore the importance of high-resolution studies for understanding the origins and spatial differentiation of COMs and carbon-chain molecules in cold, quiescent environments.
We observe the magnetic field morphology towards a nearby star-forming filamentary cloud, G202.3+2.5, by the JCMT/POL-2 850 {\mu}m thermal dust polarization observation with an angular resolution of 14.4" (~0.053 pc). The average magnetic field orientation is found to be perpendicular to the filaments while showing different behaviors in the four subregions, suggesting various effects from filaments' collision in these subregions. With the kinematics obtained by N2H+ observation by IRAM, we estimate the plane-of-sky (POS) magnetic field strength by two methods, the classical Davis-Chandrasekhar-Fermi (DCF) method and the angular dispersion function (ADF) method, B_{pos,dcf} and B_{pos,adf} are ~90 {\mu}G and ~53 {\mu}G. We study the relative importance between the gravity (G), magnetic field (B) and turbulence (T) in the four subregions, find G > T > B, G >= T > B, G ~ T > B and T > G > B in the north tail, west trunk, south root and east wing, respectively. In addition, we investigate the projection effect on the DCF and ADF methods based on a similar simulation case and find the 3D magnetic field strength may be underestimated by a factor of ~3 if applying the widely-used statistical B_{pos}-to-B_{3D} factor when using DCF or ADF method, which may further underestimate/overestimate related parameters.
Academia SinicaCalifornia Institute of Technology logoCalifornia Institute of TechnologyUniversity of OsloUniversity of Cambridge logoUniversity of CambridgeChinese Academy of Sciences logoChinese Academy of SciencesUniversity of Manchester logoUniversity of ManchesterUniversity of Southern California logoUniversity of Southern CaliforniaUniversity of Oxford logoUniversity of OxfordUniversity of California, Irvine logoUniversity of California, IrvineUniversity of BonnUniversity of Copenhagen logoUniversity of CopenhagenThe University of EdinburghUniversity of LjubljanaSokendaiETH Zürich logoETH ZürichUniversity of CreteUniversity of Texas at Austin logoUniversity of Texas at AustinUniversity of GranadaUniversity of the Basque Country (UPV/EHU)Université Paris-Saclay logoUniversité Paris-SaclayUniversity of HelsinkiUniversity of ZagrebUniversité de GenèveAalto University logoAalto UniversityCEA logoCEAUniversity of GenevaUniversity of PortsmouthUniversity of FerraraMax Planck Institute for AstrophysicsUniversity of SussexUniversity of TartuINAF - Osservatorio Astrofisico di TorinoUniversity of FlorenceUniversity of JyväskyläUniversity of PadovaInstituto de Astrofísica de CanariasUniversity of NottinghamEuropean Space AgencySISSA — International School for Advanced StudiesUniversity of TriesteUniversity of LisbonINFN, Sezione di TorinoUniversity of Hawai’iUniversity of KwaZulu-NatalUniversity of California RiversideUniversity of the Western CapeUniversity of BarcelonaNational Observatory of AthensLaboratoire d’Astrophysique de MarseilleKavli IPMU (WPI), UTIAS, The University of TokyoINAF-Istituto di RadioastronomiaINAF - Osservatorio di Astrofisica e Scienza dello SpazioINAF – Osservatorio Astronomico di RomaInstitut d’Estudis Espacials de Catalunya (IEEC)INFN - Sezione di PadovaINAF - Osservatorio Astronomico di ArcetriInstitute for Astronomy, University of HawaiiINAF-IASF MilanoKapteyn Astronomical Institute, University of GroningenLudwig Maximilians UniversityInstitut d’Astrophysique SpatialeThe Oskar Klein Centre for Cosmoparticle PhysicsDTU SpaceCRAL, Observatoire de LyonUniversity of AarhusINFN-Sezione di BolognaINFN Sezione di RomaINAF-Osservatorio Astronomico di BolognaLeiden ObservatoryUniversité de LausanneUniversity of StockholmUniversité de ProvenceFinnish Centre for Astronomy with ESO (FINCA)Laboratoire de Physique Subatomique et de CosmologieBarcelona Institute of Science and TechnologyAIM, CEA, CNRS, Université Paris-SaclayInstituto de Astrofísica e Ciências do Espaço, Universidade de LisboaWarsaw University ObservatoryNOVA Optical Infrared Instrumentation Group at ASTRONInstitute for Theoretical Physics, University of ZurichInstitute of Theoretical Astrophysics, University of OsloAstronomical Observatory of BelgradeNAOJDARK Cosmology CentreIRAP, Université de Toulouse, CNRS, CNESInstitute for Advanced Study, University of AmsterdamDanish Space Research InstituteDepartment of Physics & Astronomy, University of SussexInfrared Processing and Analysis Center, CaltechAPC, UMR 7164, CNRS, Université Paris Diderot-ParisINFN-Sezione di FerraraInstitute of Space Sciences (ICE–CSIC)Universit de ParisJodrell Bank Centre for Astrophysics The University of ManchesterINAF Osservatorio Astronomico di CapodimonteUniversit de StrasbourgMax Planck-Institute for Extraterrestrial PhysicsUniversit de LyonINAF Osservatorio Astronomico di PadovaUniversit de MontpellierINAF Osservatorio di Astrofisica e Scienza dello Spazio di BolognaINFN Sezione di TriesteINAF ` Osservatorio Astronomico di TriesteExcellence Cluster 'Universe'INAF Osservatorio Astronomico di BreraUniversity of Milano Bicocca
Euclid will provide deep NIR imaging to \sim26.5 AB magnitude over \sim59 deg2^2 in its deep and auxiliary fields. The Cosmic DAWN survey complements the deep Euclid data with matched depth multiwavelength imaging and spectroscopy in the UV--IR to provide consistently processed Euclid selected photometric catalogs, accurate photometric redshifts, and measurements of galaxy properties to a redshift of z10z\sim 10. In this paper, we present an overview of the survey, including the footprints of the survey fields, the existing and planned observations, and the primary science goals for the combined data set.
University of Amsterdam logoUniversity of AmsterdamCalifornia Institute of Technology logoCalifornia Institute of TechnologyUniversity of Illinois at Urbana-Champaign logoUniversity of Illinois at Urbana-ChampaignUniversity of Waterloo logoUniversity of WaterlooUniversity of Chicago logoUniversity of ChicagoUniversity of Science and Technology of China logoUniversity of Science and Technology of ChinaSokendaiCornell University logoCornell UniversityMcGill University logoMcGill UniversityBoston University logoBoston UniversityUniversity of CreteKorea Astronomy and Space Science InstituteRadboud UniversityUniversity of Arizona logoUniversity of ArizonaPerimeter Institute for Theoretical Physics logoPerimeter Institute for Theoretical PhysicsAalto University logoAalto UniversityUniversity of Colorado BoulderNational Radio Astronomy ObservatoryUniversity of CaliforniaJagiellonian UniversityInstituto de Astrofísica de CanariasMax-Planck-Institut für RadioastronomieUniversity of MassachusettsAcademia Sinica Institute of Astronomy and AstrophysicsHarvard-Smithsonian Center for Astrophysics logoHarvard-Smithsonian Center for AstrophysicsJoint Institute for VLBI ERICDublin Institute for Advanced StudiesLebedev Physical InstituteEast Asian ObservatoryShanghai Astronomical ObservatorySKA ObservatoryUniversity of ValenciaThe Graduate University for Advanced StudiesNiels Bohr Institute, University of CopenhagenUK Astronomy Technology CentreINAF-Istituto di RadioastronomiaInstituto de Astrofísica de AndalucíaMIT Haystack ObservatoryOnsala Space ObservatoryUniversidad de GuadalajaraSteward ObservatoryPulkovo ObservatoryNational Astronomical Observatories of ChinaInstitut de RadioAstronomie MillimétriqueNAOJDunlap Institute for Astronomy & AstrophysicsGoethe-University, FrankfurtUniversity of ConcepcinInstituto de Radioastronoma y Astrof´ısicaUniversit de BordeauxCenter for Astrophysics  Harvard & Smithsonian":
The 2017 observing campaign of the Event Horizon Telescope (EHT) delivered the first very long baseline interferometry (VLBI) images at the observing frequency of 230 GHz, leading to a number of unique studies on black holes and relativistic jets from active galactic nuclei (AGN). In total, eighteen sources were observed: the main science targets, Sgr A* and M87 along with various calibrators. We investigated the morphology of the sixteen AGN in the EHT 2017 data set, focusing on the properties of the VLBI cores: size, flux density, and brightness temperature. We studied their dependence on the observing frequency in order to compare it with the Blandford-Königl (BK) jet model. We modeled the source structure of seven AGN in the EHT 2017 data set using linearly polarized circular Gaussian components and collected results for the other nine AGN from dedicated EHT publications, complemented by lower frequency data in the 2-86 GHz range. Then, we studied the dependences of the VLBI core flux density, size, and brightness temperature on the frequency measured in the AGN host frame. We compared the observations with the BK jet model and estimated the magnetic field strength dependence on the distance from the central black hole. Our results indicate a deviation from the standard BK model, particularly in the decrease of the brightness temperature with the observing frequency. Either bulk acceleration of the jet material, energy transfer from the magnetic field to the particles, or both are required to explain the observations.
One of the most poorly understood aspects of low-mass star formation is how multiple-star systems are formed. Here we present the results of Atacama Large Millimeter/submillimeter Array (ALMA) Band-6 observations towards a forming quadruple protostellar system, G206.93-16.61E2, in the Orion B molecular cloud. ALMA 1.3 mm continuum emission reveals four compact objects, of which two are Class I young stellar objects (YSOs), and the other two are likely in prestellar phase. The 1.3 mm continuum emission also shows three asymmetric ribbon-like structures that are connected to the four objects, with lengths ranging from \sim500 au to \sim2200 au. By comparing our data with magneto-hydrodynamic (MHD) simulations, we suggest that these ribbons trace accretion flows and also function as gas bridges connecting the member protostars. Additionally, ALMA CO J=2-1 line emission reveals a complicated molecular outflow associated with G206.93-16.61E2 with arc-like structures suggestive of an outflow cavity viewed pole-on.
We report discovery of two CO clouds which are likely falling down to the Galactic plane at more than 3535 km s1^{-1}. The clouds show head-tail distributions elongated perpendicular to the Galactic plane at l=331.6l=331.6^{\circ} and b=0b=0^{\circ} as revealed by an analysis of the Mopra CO J=J=1-0 survey data. We derived the distance of the clouds to be 2.46±0.182.46 \pm 0.18 kpc based on the Gaia Data Release 3. The CO clouds have molecular masses of 4.8×103 M4.8\times 10^3\ M_{\odot} and 3.5×103 M3.5\times 10^3\ M_{\odot}, respectively, and show kinetic temperature of 30-50 K as derived from the line intensities of the 13^{13}CO JJ=2-1, 12^{12}CO JJ=1-0, and 13^{13}CO JJ=1-0 emission. The temperature in the heads of the clouds is significantly higher than 10 K of the typical molecular clouds, although no radiative heat source is found inside or close to the clouds. Based on the results, we interpret that the present clouds are falling onto the Milky Way disk and are significantly heated up by the strong shock interaction with the disk HI gas. We suggest that the clouds represent part of the HI intermediate velocity clouds falling to the Galactic plane which were converted into molecular clouds by shock compression. This is the first case of falling CO clouds having direct observed signatures of the falling motion including clear directivity and shock heating. Possible implications of the CO clouds in the evolution of the Galactic interstellar medium are discussed.
Little Red Dots (LRDs) are compact, point-like sources characterized by their red color and broad Balmer lines, which have been debated to be either dominated by active galactic nuclei (AGN) or dusty star-forming galaxies (DSFGs). Here we report two LRDs (ID9094 and ID2756) at zspec_{\rm spec}>7, recently discovered in the JWST FRESCO GOODS-North field. Both satisfy the "v-shape" colors and compactness criteria for LRDs and are identified as Type-I AGN candidates based on their broad Hβ\beta emission lines (full width at half maximum: 2280±\pm490 km/s for ID9094 and 1070±\pm240 km/s for ID2756) and narrow [OI] lines (\sim 300-400 km/s). To investigate their nature, we conduct deep NOEMA follow-up observations targeting the [CII] 158μm{\rm \mu m} emission line and the 1.3 mm dust continuum. We do not detect [CII] or 1.3 mm continuum emission for either source. Notably, in the scenario that the two LRDs were DSFGs, we would expect significant detections: >16σ>16\sigma for [CII] and >3σ>3\sigma for the 1.3 mm continuum of ID9094, and >5σ>5\sigma for [CII] of ID2756. Using the 3σ\sigma upper limits of [CII] and 1.3 mm, we perform two analyses: (1) UV-to-FIR spectral energy distribution (SED) fitting with and without AGN components, and (2) comparison of their properties with the L[CII]_{[CII]}-SFRtot_{tot} empirical relation. Both analyses are consistent with a scenario where AGN activity may contribute to the observed properties, though a dusty star-forming origin cannot be fully ruled out. Our results highlight the importance of far-infrared observations for studying LRDs, a regime that remains largely unexplored.
We have conducted ALMA CO isotopes and 1.3 mm continuum observations toward filamentary molecular clouds of the N159W-South region in the Large Magellanic Cloud with an angular resolution of \sim0"25 (\sim0.07 pc). Although the previous lower-resolution (\sim1") ALMA observations revealed that there is a high-mass protostellar object at an intersection of two line-shaped filaments in 13^{13}CO with the length scale of \sim10 pc, the spatially resolved observations, in particular, toward the highest column density part traced by the 1.3 mm continuum emission, the N159W-South clump, show complicated hub-filamentary structures. We also discovered that there are multiple protostellar sources with bipolar outflows along the massive filament. The redshifted/blueshifted components of the 13^{13}CO emission around the massive filaments/protostars have complementary distributions, which is considered to be a possible piece of evidence for a cloud-cloud collision. We propose a new scenario in which the supersonically colliding gas flow triggers the formation of both the massive filament and protostars. This is a modification of the earlier scenario of cloud-cloud collision, by Fukui et al., that postulated the two filamentary clouds occur prior to the high-mass star formation. A recent theoretical study of the shock compression in colliding molecular flows by Inoue et al. demonstrates that the formation of filaments with hub structure is a usual outcome of the collision, lending support for the present scenario. The theory argues that the filaments are formed as dense parts in a shock compressed sheet-like layer, which resembles ""an umbrella with pokes.""
In 2017, the next generation Very Large Array (ngVLA) Science Advisory Council, together with the international astronomy community, developed a set of five Key Science Goals (KSGs) to inform, prioritize and refine the technical capabilities of a future radio telescope array for high angular resolution operation from 1.2 - 116 GHz with 10 times the sensitivity of the Jansky VLA and ALMA. The resulting KSGs, which require observations at centimeter and millimeter wavelengths that cannot be achieved by any other facility, represent a small subset of the broad range of astrophysical problems that the ngVLA will be able address. This document presents an update to the original ngVLA KSGs, taking account of new results and progress in the 7+ years since their initial presentation, again drawing on the expertise of the ngVLA Science Advisory Council and the broader community in the ngVLA Science Working Groups. As the design of the ngVLA has also matured substantially in this period, this document also briefly addresses initial expectations for ngVLA data products and processing that will be needed to achieve the KSGs. The original ngVLA KSGs endure as outstanding problems of high priority. In brief, they are: (1) Unveiling the Formation of Solar System Analogues; (2) Probing the Initial Conditions for Planetary Systems and Life with Astrochemistry; (3) Charting the Assembly, Structure, and Evolution of Galaxies from the First Billion Years to the Present; (4) Science at the Extremes: Pulsars as Laboratories for Fundamental Physics; (5) Understanding the Formation and Evolution of Stellar and Supermassive Black Holes in the Era of Multi-Messenger Astronomy.
CASA, the Common Astronomy Software Applications package, is the primary data processing software for the Atacama Large Millimeter/submillimeter Array (ALMA) and NSF's Karl G. Jansky Very Large Array (VLA), and is frequently used also for other radio telescopes. The CASA software can process data from both single-dish and aperture-synthesis telescopes, and one of its core functionalities is to support the data reduction and imaging pipelines for ALMA, VLA and the VLA Sky Survey (VLASS). CASA has recently undergone several exciting new developments, including an increased flexibility in Python (CASA 6), support of Very Long Baseline Interferometry (VLBI), performance gains through parallel imaging, data visualization with the new Cube Analysis Rendering Tool for Astronomy (CARTA), enhanced reliability and testing, and modernized documentation. These proceedings of the 2019 Astronomical Data Analysis Software & Systems (ADASS) conference give an update of the CASA project, and detail how these new developments will enhance user experience of CASA.
The current progress in the detection of terrestrial type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favorable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of astrospheric, atmospheric and surface environments of exoplanets in habitable zones around G-K-M dwarfs including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles, and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favorable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro) physical, chemical, and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the habitable zone to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.
We have carried out wide-field (0.17 degree^2) and high-angular resolution (21.3 arcsec ~ 0.04 pc) observations in [CI] line toward the Orion-A giant molecular cloud with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope in the On-The-Fly (OTF) mode. Overall features of the [CI] emission are similar to those of the CO (1--0) emission in Shimajiri et al. (2011); the total intensity ratio of the [CI] to CO emission ranges from 0.05 to 0.2. The optical depth of the [CI] emission is found to be 0.1 -- 0.75, suggesting optically thin emission. The column density of the [CI] emission is estimated to be (1.0 -- 19) x 10^17 cm^-2. These results are consistent with the results of the previous [CI] observations with a low-angular resolution of 2.2 arcmin (e.g. Ikeda et al. 1999). In the nearly edge-on PDRs and their candidates of the Orion Bar, DLSF, M 43 Shell, and Region D, the distributions of the [CI] emission coincide with those of the CO emission, inconsistent with the prediction by the plane-parallel PDR model (Hollenbach & Tielens 1999). In addition, the [CI] distribution in the Orion A cloud is found to be more similar to those of the ^{13}CO (1--0), C^{18}O (1--0), and H^{13}CO^+ (1--0) lines than that of the CO (1--0) line, suggesting that the [CI] emission is not limited to the cloud surface, but is tracing the dense, inner parts of the cloud.
Recent observations of the nearby Galactic molecular clouds indicate that the dense gas in molecular clouds have quasi-universal properties on star formation, and observational studies of extra galaxies have shown a galactic-scale correlation between the star formation rate (SFR) and surface density of molecular gas. To reach a comprehensive understanding of both properties, it is important to quantify the fractional mass of the dense gas in molecular clouds f_DG. In particular, for the Milky Way (MW), there are no previous studies resolving the f_DG disk over a scale of several kpc. In this study, the f_DG was measured over 5kpc in the first quadrant of the MW, based on the CO J=1-0 data in l=10-50 deg obtained as part of the FOREST Unbiased Galactic Plane Imaging Survey with the Nobeyama 45-m Telescope (FUGIN) project. The total molecular mass was measured using 12CO, and the dense gas mass was estimated using C18O. The fractional masses including f_DG in the region within ~30% of the distances to the tangential points of the Galactic rotation (e.g., the Galactic Bar, Far-3kpc Arm, Norma Arm, Scutum Arm, Sagittarius Arm, and inter-arm regions) were measured. As a result, an averaged f_DG of 2.9^{+2.6}_{-2.6} % was obtained for the entirety of the target region. This low value suggests that dense gas formation is the primary factor of inefficient star formation in galaxies. It was also found that the f_DG shows large variations depending on the structures in the MW disk. The f_DG in the Galactic arms were estimated to be ~4-5%, while those in the bar and inter-arm regions were as small as ~0.1-0.4%. These results indicate that the formation/destruction processes of the dense gas and their timescales are different for different regions in the MW, leading to the differences in SFRs.
We report detections of two candidate distant submillimeter galaxies (SMGs), MM J154506.4-344318 and MM J154132.7-350320, which are discovered in the AzTEC/ASTE 1.1 mm survey toward the Lupus-I star-forming region. The two objects have 1.1 mm flux densities of 43.9 and 27.1 mJy, and have Herschel/SPIRE counterparts as well. The Submillimeter Array counterpart to the former SMG is identified at 890 μ\mum and 1.3 mm. Photometric redshift estimates using all available data from the mid-infrared to the radio suggest that the redshifts of the two SMGs are zphotoz_{\rm photo} \simeq 4-5 and 3, respectively. Near-infrared objects are found very close to the SMGs and they are consistent with low-zz ellipticals, suggesting that the high apparent luminosities can be attributed to gravitational magnification. The cumulative number counts at S1.1mm25S_{\rm 1.1mm} \ge 25 mJy, combined with other two 1.1-mm brightest sources, are 0.700.34+0.560.70 ^{+0.56}_{-0.34} deg2^{-2}, which is consistent with a model prediction that accounts for flux magnification due to strong gravitational lensing. Unexpectedly, a z>3z > 3 SMG and a Galactic dense starless core (e.g., a first hydrostatic core) could be similar in the mid-infrared to millimeter spectral energy distributions and spatial structures at least at 1"\gtrsim 1". This indicates that it is necessary to distinguish the two possibilities by means of broad band photometry from the optical to centimeter and spectroscopy to determine the redshift, when a compact object is identified toward Galactic star-forming regions.
The HR 8799 system uniquely harbors four young super-Jupiters whose orbits can provide insights into the system's dynamical history and constrain the masses of the planets themselves. Using the Gemini Planet Imager (GPI), we obtained down to one milliarcsecond precision on the astrometry of these planets. We assessed four-planet orbit models with different levels of constraints and found that assuming the planets are near 1:2:4:8 period commensurabilities, or are coplanar, does not worsen the fit. We added the prior that the planets must have been stable for the age of the system (40 Myr) by running orbit configurations from our posteriors through NN-body simulations and varying the masses of the planets. We found that only assuming the planets are both coplanar and near 1:2:4:8 period commensurabilities produces dynamically stable orbits in large quantities. Our posterior of stable coplanar orbits tightly constrains the planets' orbits, and we discuss implications for the outermost planet b shaping the debris disk. A four-planet resonance lock is not necessary for stability up to now. However, planet pairs d and e, and c and d, are each likely locked in two-body resonances for stability if their component masses are above 6 MJup6~M_{\rm{Jup}} and 7 MJup7~M_{\rm{Jup}}, respectively. Combining the dynamical and luminosity constraints on the masses using hot-start evolutionary models and a system age of 42±542 \pm 5~Myr, we found the mass of planet b to be $5.8 \pm 0.5~M_{\rm{Jup}}$, and the masses of planets c, d, and e to be 7.20.7+0.6 MJup7.2_{-0.7}^{+0.6}~M_{\rm{Jup}} each.
We present Orion A giant molecular cloud core catalogs, which are based on 1.1 mm map with an angular resolution of 36 arcsec (sim 0.07 pc) and C18O (1-0) data with an angular resolution of 26.4 arcsec (sim 0.05 pc). We have cataloged 619 dust cores in the 1.1 mm map using the Clumpfind method. The ranges of the radius, mass, and density of these cores are estimated to be 0.01 - 0.20 pc, 0.6 - 1.2 times 10^2 Msun, and 0.3 times 10^4 - 9.2 times 10^6 cm^{-3}, respectively. We have identified 235 cores from the C18O data. The ranges of the radius, velocity width, LTE mass, and density are 0.13 -- 0.34 pc, 0.31 - 1.31 km s^{-1}, 1.0 - 61.8 Msun, and (0.8 - 17.5) times 10^3 cm^{-3}, respectively. From the comparison of the spatial distributions between the dust and C18O cores, four types of spatial relations were revealed: (1) the peak positions of the dust and C18O cores agree with each other (32.4% of the C18O cores), (2) two or more C18O cores are distributed around the peak position of one dust core (10.8% of the C18O cores), (3) 56.8% of the C18O cores are not associated with any dust cores, and (4) 69.3% of the dust cores are not associated with any C18O cores. The data sets and analysis are public.
The r-process nucleosynthesis in core-collapse supernovae (CC-SNe) is studied, with a focus on the explosion scenario induced by rotation and strong magnetic fields. Nucleosynthesis calculations are conducted based on magneto-hydrodynamical explosion models with a wide range of parameters for initial rotation and magnetic fields. The explosion models are classified in two different types: i.e., prompt-magnetic-jet and delayed-magnetic-jet, for which the magnetic fields of proto-neutron stars (PNSs) during collapse and the core-bounce are strong and comparatively moderate, respectively. Following the hydrodynamical trajectories of each explosion model, we confirmed that r-processes successfully occur in the prompt-magnetic-jets, which produce heavy nuclei including actinides. On the other hand, the r-process in the delayed-magnetic-jet is suppressed, which synthesizes only nuclei up to the second peak (A130A \sim 130). Thus, the r-process in the delayed-magnetic-jets could explain only "weak r-process" patterns observed in metal-poor stars rather than the "main r-process", represented by the solar abundances. Our results imply that core-collapse supernovae are possible astronomical sources of heavy r-process elements if their magnetic fields are strong enough, while weaker magnetic explosions may produce "weak r-process" patterns (A130A \lesssim 130). We show the potential importance and necessity of magneto-rotational supernovae for explaining the galactic chemical evolution, as well as abundances of r-process enhanced metal-poor stars. We also examine the effects of the remaining uncertainties in the nature of PNSs due to weak interactions that determine the final neutron-richness of ejecta. Additionally, we briefly discuss radioactive isotope yields in primary jets (e.g., 56^{56}Ni), with relation to several optical observation of SNe and relevant high-energy astronomical phenomena.
M16, the Eagle Nebula, is an outstanding HII region where extensive high-mass star formation is taking place in the Sagittarius Arm, and hosts the remarkable "pillars" observed with HST. We made new CO observations of the region in the 12CO J=1--0 and J=2--1 transitions with NANTEN2. These observations revealed for the first time that a giant molecular cloud of 1.3×105\sim 1.3 \times 10^5 \Msun \ is associated with M16, which is elongated vertically to the Galactic plane over 35 pc at a distance of 1.8 kpc. We found a cavity of the molecular gas of 10\sim 10 pc diameter toward the heart of M16 at \lbeq (16.95\degree, 0.85\degree), where more than 10 O-type stars and 400\sim 400 stars are associated, in addition to a close-by molecular cavity toward a Spitzer bubble N19 at \lbeq (17.06\degree, 1.0\degree). We found three velocity components which show spatially complementary distribution in the entire M16 giant molecular cloud (GMC) including NGC6611 and N19, suggesting collisional interaction between them. Based on the above results we frame a hypothesis that collision between the red-shifted and blue-shifted components at a relative of 10\sim 10 \kms \ triggered formation of the O-type stars in the M16 GMC in the last 1-2 Myr. The collision is two fold in the sense that one of the collisional interactions is major toward the M16 cluster and the other toward N19 with a RCW120 type, the former triggered most of the O star formation with almost full ionization of the parent gas, and the latter an O star formation in N19.
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