Article
Astronomy & Astrophysics
Benoit Tabone, Marc C. van Hemert, Ewine F. van Dishoeck, John H. Black
Summary: This study proposes a method to quantify the photodissociation rate of H2O and measure the local UV field using observations of OH lines. Factors influencing the photodissociation rate and line intensities are studied.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Bo Reipurth, Per Friberg
Summary: The isolated Herbig-Haro object HH 175 is a terminal shock in a large collimated outflow originating from the nearby embedded source IRAS 05417+0907 towards the B35 cloud in the lambda Ori region. The eastern outflow lobe is hidden by a dense gas ridge, while the western outflow breaks out of the cometary-shaped B35 cloud, carrying visible cloud fragments due to photoionization by the massive stars in the area.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
S. J. D. Purser, S. L. Lumsden, M. G. Hoare, S. Kurtz
Summary: This study presents the largest radio survey of jets from massive protostars. The research shows a correlation between radio luminosity and bolometric luminosity in jet production, and suggests that most jets are capable of driving massive molecular outflow phenomena.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
F. Massi, R. Lopez, M. T. Beltran, R. Estalella, J. M. Girart
Summary: This study characterizes the kinematics and physical conditions of H-2 emission features in the IC 1396N region. The results reveal a chain-like morphology with jet-like features and trace different H-2 outflows. The knots exhibit complex kinematic structures.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Luis F. Miranda, Jose M. Torrelles, Jorge Lillo-Box
Summary: IC 4997, a well-known planetary nebula, has been found to exhibit variability in its emission line profiles. Recent high-resolution spectra reveal changes in the H alpha and [N II] emission profiles, including a shift from P Cygni to single-peaked profiles for H alpha and a narrowing of the broad emission wings. The high-velocity [N II] nebular component detected in 1993 is absent in 2019 and 2020.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
U. Kavak, A. Sanchez-Monge, A. Lopez-Sepulcre, R. Cesaroni, F. F. S. van der Tak, L. Moscadelli, M. T. Beltran, P. Schilke
Summary: The study aims to increase the number of known radio jets in high-mass star-forming regions by searching for radio-jet candidates at radio continuum wavelengths. The results show that about 60% of the radio continuum sources detected within the field of view are potential radio jets, and the detection of radio jets in high-mass star-forming regions is more likely in slightly more evolved regions.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Soumen Deb, Roland Kothes, Erik Rosolowsky
Summary: This paper analyzes 13 outflows in the Cygnus X star-forming region using new observations and develops a method to measure their properties using existing line data. The results show consistency in mechanical properties and associated protostars. The developed method shows agreement in properties within a factor of 2.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
T. A. Movsessian, T. Yu. Magakian, A. V. Moiseev
Summary: The study focuses on the kinematics and physical properties of spectrally separated structures in the HH 83 flow, uncovering a counter bow-shock with positive radial velocity and two structures with significantly different radial velocities. The findings suggest a collision between the outflow and a dense cloud, while the H alpha line profile of HH 83 IRS indicates characteristics of FU Ori-like objects.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Michael D. Smith, Carl Richards
Summary: The Mach number is a crucial parameter in determining the driving properties and impact on the environment of a supersonic jet. Through numerical simulations, we investigate the effects of different Mach numbers and jet overpressures on the flow pattern and shock locations. We also analyze potential observational diagnostics and the energy transferred into the environment.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Mauricio Tapia, Paolo Persi
Summary: The well-studied massive star-forming region IRAS 23139+5939 is found to be a multiple massive young stellar object with Class I spectral energy distribution. It is associated with methanol and water masers, compact H ii regions, and H-2 emission knots. There is also a young embedded stellar cluster with evidence of protoplanetary discs. Gaia Data Release 3 and parallaxes indicate a common distance of 3.34 kpc to IRAS 23139+5939 and a nearby H alpha-emission star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. H. Cerqueira, B. Lefloch, A. Esquivel, P. R. Rivera-Ortiz, C. Codella, C. Ceccarelli, L. Podio
Summary: The study revisits the physical origin of the mass-velocity relationship in jet-driven protostellar outflows and investigates the contributions of different regions of the outflow. The research finds that excluding the jet contribution, the mass-velocity relationship can be well described by a single exponential law, while the jet contribution results in additional components in the mass-velocity relationship.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. E. Ortega, A. Marinelli, N. L. Isequilla, S. Paron
Summary: The study reveals that the massive clump AGAL35 contains four low- to intermediate-mass cores, providing important insights into the interstellar fragmentation processes and early star formation activities.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Rosario Lopez, Angels Riera, Robert Estalella, Gabriel Gomez
Summary: Jets and outflows are commonly associated with young stellar objects, and their morphology can be spatially discontinuous due to temporal variability. This study aimed to search for large-scale optical Herbig-Haro objects around a sample of IRAS sources to trace young stellar objects. Deep narrowband images were used to analyze shock-excited line emission and scattered line emission for a sample of 15 IRAS sources.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. M. Vazzano, M. Fernandez-Lopez, A. Plunkett, I. De Gregorio-Monsalvo, A. Santamaria-Miranda, S. Takahashi, C. Lopez
Summary: The study aims to test the coherence between commonly used evolutionary tracers by observing seven objects in the Lupus clouds at different evolutionary stages. The findings reveal that the evolutionary classification aligns with previous studies except for one source, suggesting a need for more detailed observations to refine classifications. The study also indicates that the most common evolutionary tracers in the literature are useful for broad classifications but lack consistency to differentiate sources within the same Class.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
S. Paron, D. Mast, C. Farina, M. B. Areal, M. E. Ortega, N. C. Martinez, M. Celis Pena
Summary: This study presents detailed observations and analysis of the galactic source G79, revealing the presence of a precessing jet with corkscrew-like structures and a C-type shock bow shock. These findings provide observational evidence to support theoretical models of bow shocks and precessing jets.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Santamaria-Miranda, I. de Gregorio-Monsalvo, A. L. Plunkett, N. Huelamo, C. Lopez, A. Ribas, M. R. Schreiber, K. Muzic, A. Palau, L. B. G. Knee, A. Bayo, F. Comeron, A. Hales
Summary: The study aims to identify and characterize pre- and proto-BDs, as well as Class II BDs in Lupus 1 and 3 molecular clouds using ALMA observations. The results suggest that the sources in the sample are likely formed as a scaled-down version of low-mass star formation, with disk fragmentation potentially responsible for a considerable fraction of BDs.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Gilberto C. Gomez, Enrique Vazquez-Semadeni, Aina Palau
Summary: The study focuses on the gravitational and accretion driven evolution of a prestellar core, showing that as the density of the core increases, it accretes from its environment, increasing mass and decreasing Jeans length. The slope of the density distribution peaks around p approximately 1.7-1.9, implying that the density profile steepens over time. Magnetic support in cores suggests a decrease in mass to magnetic flux ratio towards the center, making them appear magnetically supported, although they may actually be part of a larger collapsing region.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Aina Palau, Qizhou Zhang, Josep M. Girart, Junhao Liu, Ramprasad Rao, Patrick M. Koch, Robert Estalella, Huei-Ru Vivien Chen, Hauyu Baobab Liu, Keping Qiu, Zhi-Yun Li, Luis A. Zapata, Sylvain Bontemps, Paul T. P. Ho, Henrik Beuther, Tao-Chung Ching, Hiroko Shinnaga, Aida Ahmadi
Summary: Theoretical and numerical studies suggest that a strong magnetic field can suppress fragmentation in dense cores, but this has not been observationally tested in a large sample. By studying 18 massive dense cores, a strong correlation is found between fragmentation level and the average density of the parental core.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Jacob Aaron White, F. Tapia-Vazquez, A. G. Hughes, A. Moor, B. Matthews, D. Wilner, J. Aufdenberg, O. Feher, A. M. Hughes, V. De la Luz, A. McNaughton, L. A. Zapata
Summary: The radio spectra of main-sequence stars are still largely unknown due to lack of observational data. By observing the rapidly rotating A-type star Altair, researchers found unexpected brightness temperature patterns and generated the first observational-informed radio spectrum for such a star. This study reveals the presence of a chromosphere in A-type stars, likely induced by rapid rotation, challenging previous assumptions about star's radio spectra.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
Mengyao Tang, Aina Palau, Luis A. Zapata, Sheng-Li Qin
Summary: The study focuses on the fragmentation process in massive star-forming regions, specifically investigating W51 IRS2 using high angular resolution data from ALMA. A total of 33 continuum sources were identified, with 29 defined as fragments. Analysis of mean surface density of companions revealed two breaks indicating a two-level clustering phenomenon in the region.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Shanghuo Li, Patricio Sanhueza, Chang Won Lee, Qizhou Zhang, Henrik Beuther, Aina Palau, Hong-Li Liu, Howard A. Smith, Hauyu Baobab Liu, Izaskun Jimenez-Serra, Kee-Tae Kim, Siyi Feng, Tie Liu, Junzhi Wang, Di Li, Keping Qiu, Xing Lu, Josep Miquel Girart, Ke Wang, Fei Li, Juan Li, Yue Cao, Shinyoung Kim, Shaye Strom
Summary: This study presents the observation results of narrow filaments in the NGC 6334S infrared dark cloud using ALMA. The filaments are found to be narrower and have lower turbulence compared to previously proposed filaments. Embedded cores show smaller widths and lower velocity dispersions compared to their corresponding filaments. The physical properties of the filaments are analogous to those found in low- to high-mass star-forming regions.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Daniel Tafoya, Jesus A. Toala, Ramlal Unnikrishnan, Wouter H. T. Vlemmings, Martin A. Guerrero, Stefan Kimeswenger, Peter A. M. van Hoof, Luis A. Zapata, Sandra P. Trevino-Morales, Janis B. Rodriguez-Gonzalez
Summary: This study presents ALMA observations of a born-again star, revealing the distribution and kinematic properties of its associated molecular material. The majority of the observed molecular emission is produced in a radially expanding disk-like structure, while a high-velocity bipolar outflow component is also detected. The dust mass and CO mass of the born-again star are estimated to be relatively large, consistent with previous hypotheses.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Gilberto C. Gomez, Catherine Walsh, Aina Palau
Summary: This study explores how the measurement of dense filament widths using different molecular species can be influenced by gas accretion. The abundance of various molecules is affected differently by the changing environment as a gas parcel falls into the filament. The widths of filaments measured from time-dependent abundances of certain molecules are most sensitive to this effect, while others are less sensitive. The ratios of filament widths for different tracers could be a useful tool for estimating the accretion rate onto the filament.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. de Valon, C. Dougados, S. Cabrit, F. Louvet, L. A. Zapata, D. Mardones
Summary: This study characterizes the morphology and kinematics of the DG Tau B outflow and suggests that it may be caused by jet bow shocks, source orbital motion, or disk density perturbations rather than wind-driven shell models. These findings provide the strongest evidence so far for the presence of massive MHD disk winds in Class I sources with residual infall and suggest that the initial stages of planet formation occur in a highly dynamic environment.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Luis A. Zapata, Laurent Loinard, Manuel Fernandez-Lopez, Jesus A. Toala, Ricardo F. Gonzalez, Luis F. Rodriguez, Theodore R. Gull, Patrick W. Morris, Karl M. Menten, Tomasz Kaminski
Summary: This study presents observations of the molecular gas component in the circumstellar vicinity of eta Carinae, revealing its origin and kinematics. The observations show high-velocity blue- and redshifted molecular thermal emission, as well as an inner butterfly-shaped structure at systemic velocities.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Estrella Guzman Ccolque, Manuel Fernandez-Lopez, Luis A. Zapata, Tapas Baug
Summary: In this study, observations of the IRAS 16076-5134 high-mass star formation region were retrieved from the ALMA archives, revealing 14 dense cores and a filament-like CO outflow. The filaments show radial expansion and explosive characteristics, suggesting the presence of a dispersal outflow. In addition, a preliminary estimation of the frequency rate of explosive dispersal outflows in the galaxy was made, indicating their potential importance in the energy budget and connection to high-mass star formation.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
O. S. Rojas-Garcia, A. Gomez-Ruiz, A. Palau, M. T. Orozco-Aguilera, M. Chavez Dagostino, S. E. Kurtz
Summary: The interstellar medium contains dust and gas, in which complex organic molecules (iCOMs) can proliferate at high densities and in cold conditions. In this study, we analyzed the presence of iCOMs in the outflow component of massive protostars and found a correlation between iCOMs and large-scale low-velocity outflows.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
Vianey Camacho, Enrique Vazquez-Semadeni, Aina Palau, Manuel Zamora-Aviles
Summary: We conducted a numerical study on the balance of gravitational, kinetic, and magnetic energies in hub-filament structures within a giant molecular cloud. The study examined the scaling relationships between the virial parameter, Larson ratio, and mass and column density of the structures. We also compared our numerical results with an observational sample of massive clumps and found similar trends. The main controlling parameter of the energy budget in the structures is gravitational energy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Luis A. Zapata, Manuel Fernandez-Lopez, Silvia Leurini, Estrella Guzman Ccolque, I. M. Skretas, Luis F. Rodriguez, Palau Aina, Karl M. Menten, Wyrowski Friedrich
Summary: In recent years, there has been a significant increase in the number of reported massive and bright star-forming regions with explosive outflows, thanks to the improved sensitivity and resolution of radio, infrared, and optical facilities. This study reports a new explosive outflow related to the star-forming region IRAS 12326-6245 using high-resolution ALMA observations. The findings include the discovery of over 10 molecular and collimated streamers with expansion motions similar to Hubble-Lemaitre, pointing towards a dusty and molecular shell localized in the northern part of the UC H ii region known as G301.1A. The estimated kinematic age and energy of the explosion are approximately 700 years and 1048 erg, respectively.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Astronomy & Astrophysics
Geovanni Cortes-Rangel, Luis A. Zapata, Pedro R. Rivera-Ortiz, Megan Reiter, Satoko Takahashi, Josep M. Masque
Summary: We present a more extensive study of dusty and gaseous pillars and globules in the Carina Nebula using ALMA observations. These observations reveal the molecular outflows, dusty envelopes+disks, and extended HH objects in these regions. The results suggest that the exciting sources may be low- or intermediate-mass protostars.
ASTROPHYSICAL JOURNAL
(2023)
