Diego Mardones | Universidad de Chile (original) (raw)

Papers by Diego Mardones

Research paper thumbnail of ALMA Studies of the Disk-Jet-Outflow Connection

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Research paper thumbnail of Star Formation from Cores To Clusters - Conference Summary

Conference summary

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Research paper thumbnail of Astrochemical Diagnostics of the Isolated Massive Protostar G28.20-0.05

arXiv (Cornell University), Mar 5, 2023

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Research paper thumbnail of The HH30 T-Tauri star

sf2a, Dec 1, 2019

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Research paper thumbnail of Studying the Outflow-Core Interaction with ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow

Astronomical Society of the Pacific eBooks, Dec 1, 2015

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Research paper thumbnail of The Envelope-Disk-Outflow System in Massive Protostellar Source G339.88-1.26

arXiv (Cornell University), Nov 11, 2018

We report molecular line observations of the massive protostellar source G339.88-1.26 with the At... more We report molecular line observations of the massive protostellar source G339.88-1.26 with the Atacama Large Millimeter/Submillimeter Array. The observations reveal a highly collimated SiO jet extending from the 1.3 mm continuum source, which connects to a slightly wider but still highly collimated CO outflow. Rotational features perpendicular to the outflow axis are detected in various molecular emissions, including SiO, SO$_2$, H$_2$S, CH$_3$OH, and H$_2$CO emissions. Based on their spatial distributions and kinematics, we find that they trace different parts of the envelope-disk system. The SiO traces the disk and inner envelope in addition to the jet, the CH$_3$OH and H$_2$CO trace the infalling-rotating envelope outside of the disk, and the SO$_2$ and H$_2$S appear enhanced around the transition region between envelope and disk, i.e., the centrifugal barrier, as well as the outer part of the disk. Envelope kinematics are consistent with rotating-infalling motion, while those of the disk are consistent with Keplerian rotation. The radius and velocity of the centrifugal barrier are estimated to be about 530 au and 6 km s$^{-1}$, leading to a central mass of about 11M˜odot11~M_\odot11M˜odot, consistent with estimates based on spectral energy distribution fitting. These results indicate that an ordered transition from an infalling-rotating envelope to a Keplerian disk through a centrifugal barrier, accompanied by change of chemical composition, is a valid description of this massive protostellar source. This implies that at least some massive stars form in a similar way as low-mass stars via Core Accretion.

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Research paper thumbnail of Unsupervised Learning of Structure in Spectroscopic Cubes

arXiv (Cornell University), Jun 14, 2018

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Research paper thumbnail of Modeling the CO outflow in DG Tauri B: Swept-up shells versus perturbed MHD disk wind

Astronomy and Astrophysics, Dec 1, 2022

Context. The origin of outflows and their exact impact on disk evolution and planet formation rem... more Context. The origin of outflows and their exact impact on disk evolution and planet formation remain crucial open questions. DG Tau B is a Class I protostar associated with a rotating conical CO outflow and a structured disk. Hence it is an ideal target to study these questions. Aims. We aim to characterize the morphology and kinematics of the DG Tau B outflow in order to elucidate its origin and potential impact on the disk. Methods. Our analysis is based on Atacama Large Millimeter Array (ALMA) 12CO(2–1) observations of DG Tau B at 0.15″ (20 au) angular resolution. We developed a tomographic method to recover 2D (R,Z) maps of vertical velocity VZ and specific angular momentum j = R × Vϕ. We created synthetic data cubes for parametric models of wind-driven shells and disk winds, which we fit to the observed channel maps. Results. Tomographic analysis of the bright inner conical outflow shows that both VZ and j remain roughly constant along conical surfaces, defining a shear-like structure. We characterize three different types of substructures in this outflow (arches, fingers, and cusps) with apparent acceleration. Wind-driven shell models with a Hubble law fail to explain these substructures. In contrast, both the morphology and kinematics of the conical flow can be explained by a steady conical magnetohydrodynamic (MHD) disk wind with foot-point radii r0 ≃ 0.7–3.4 au, a small magnetic level arm parameter (λ ≤ 1.6), and quasi periodic brightness enhancements. These might be caused by the impact of jet bow shocks, source orbital motion caused by a 25 MJ companion at 50 au, or disk density perturbations accreting through the wind launching region. The large CO wind mass flux (four times the accretion rate onto the central star) can also be explained if the MHD disk wind removes most of the angular momentum required for steady disk accretion. Conclusions. Our results provide the strongest evidence so far for the presence of massive MHD disk winds in Class I sources with residual infall, and they suggest that the initial stages of planet formation take place in a highly dynamic environment.

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Research paper thumbnail of The Role of Gas in the Merging of Massive Black Holes in Galactic Nuclei

Springer eBooks, Feb 1, 2006

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Research paper thumbnail of ALMA reveals a large structured disk and nested rotating outflows in DG Tauri B

Astronomy and Astrophysics, Feb 1, 2020

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Research paper thumbnail of The HH30 edge-on T Tauri star

Astronomy and Astrophysics, Oct 1, 2018

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Research paper thumbnail of A Collimated Stellar Wind Emanating from a Massive Protostar

Springer eBooks, 2004

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Research paper thumbnail of A three-dimensional chemical simulation with irregular density distributions of L1544

Monthly Notices of the Royal Astronomical Society, Mar 2, 2023

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Research paper thumbnail of Models of Rotating Infall for the B335 Protostar

arXiv (Cornell University), Dec 7, 2022

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Research paper thumbnail of CO(2-->1) and 13CO(1-->0) emission from luminous southern infrared galaxies

Astronomy and Astrophysics, Oct 1, 1993

, We observed, using the SEST 15-m telescope, the CO(2-1) line emission toward eight highly lumin... more , We observed, using the SEST 15-m telescope, the CO(2-1) line emission toward eight highly luminous infrared galaxies of the southern hemisphere which were previously detected in the CO(1-0) transition. While the shapes of the (2 - 1) and (1 - 0) line profiles (taken with angular resolutions of 24" and 45", respectively) are remarkably similar, the ratios of observed peak main-beam radiation temperatures vary between 1.2 and 2.6. The derived (2-1)/(1-0) ratios of velocity integrated brightness temperature range between 0.33 and 0.77, indicating that the physical conditions of the molecular gas varies from source to source. Assuming that the kinetic temperature of the molecular gas is similar to the temperature derived for the dust (~30-40 K), the low values of the integrated line ratios imply that the CO is subthermally excited and that the bulk of the emission arises from regions of moderate H_2_ density, between 100 and 500 cm^-3^. We find that the use of the Galactic CO-H_2_ conversion factor is appropriate, to within a factor of 1.5, to estimate the molecular mass in this type of galaxies. We also observed four of these galaxies in the ^13^CO(1-0) transition and one in the ^13^CO(2-1) line. The ^12^CO(1-0)/^13^CO(1-0) velocity integrated brightness temperature ratios range from 9 to 27. The largest values, about 5 times greater than the average ratio observed for molecular clouds in the Milky Way disk, are exhibited by the most luminous IR galaxies. They can be explained if molecular clouds in mergers have low and moderate optical depths in ^13^CO and ^12^CO, respectively.

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Research paper thumbnail of Formation of formaldehyde through methanol-ice-mantle (CH<sub>3</sub>OH)<sub>10</sub> bombardment by OH<sup>+</sup> cation

Astronomy and Astrophysics, Jun 1, 2021

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Research paper thumbnail of The Evolution of Protostellar Outflow Cavities, Kinematics, and Angular Distribution of Momentum and Energy in Orion A: Evidence for Dynamical Cores

arXiv (Cornell University), Feb 6, 2023

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Research paper thumbnail of A Co Survey in Planet-Forming Disks: Characterizing the Gas Content in the Epoch of Planet Formation

The Astronomical Journal, Jul 31, 2014

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Research paper thumbnail of Outflow Entrainment and Feedback: A Case Study with HH46/47 Molecular Outflow

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Research paper thumbnail of ALMA Reveals Sequential High-mass Star Formation in the G9.62+0.19 Complex

The Astrophysical Journal, Oct 26, 2017

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Research paper thumbnail of ALMA Studies of the Disk-Jet-Outflow Connection

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Research paper thumbnail of Star Formation from Cores To Clusters - Conference Summary

Conference summary

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Research paper thumbnail of Astrochemical Diagnostics of the Isolated Massive Protostar G28.20-0.05

arXiv (Cornell University), Mar 5, 2023

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Research paper thumbnail of The HH30 T-Tauri star

sf2a, Dec 1, 2019

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Research paper thumbnail of Studying the Outflow-Core Interaction with ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow

Astronomical Society of the Pacific eBooks, Dec 1, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Envelope-Disk-Outflow System in Massive Protostellar Source G339.88-1.26

arXiv (Cornell University), Nov 11, 2018

We report molecular line observations of the massive protostellar source G339.88-1.26 with the At... more We report molecular line observations of the massive protostellar source G339.88-1.26 with the Atacama Large Millimeter/Submillimeter Array. The observations reveal a highly collimated SiO jet extending from the 1.3 mm continuum source, which connects to a slightly wider but still highly collimated CO outflow. Rotational features perpendicular to the outflow axis are detected in various molecular emissions, including SiO, SO$_2$, H$_2$S, CH$_3$OH, and H$_2$CO emissions. Based on their spatial distributions and kinematics, we find that they trace different parts of the envelope-disk system. The SiO traces the disk and inner envelope in addition to the jet, the CH$_3$OH and H$_2$CO trace the infalling-rotating envelope outside of the disk, and the SO$_2$ and H$_2$S appear enhanced around the transition region between envelope and disk, i.e., the centrifugal barrier, as well as the outer part of the disk. Envelope kinematics are consistent with rotating-infalling motion, while those of the disk are consistent with Keplerian rotation. The radius and velocity of the centrifugal barrier are estimated to be about 530 au and 6 km s$^{-1}$, leading to a central mass of about 11M˜odot11~M_\odot11M˜odot, consistent with estimates based on spectral energy distribution fitting. These results indicate that an ordered transition from an infalling-rotating envelope to a Keplerian disk through a centrifugal barrier, accompanied by change of chemical composition, is a valid description of this massive protostellar source. This implies that at least some massive stars form in a similar way as low-mass stars via Core Accretion.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Unsupervised Learning of Structure in Spectroscopic Cubes

arXiv (Cornell University), Jun 14, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Modeling the CO outflow in DG Tauri B: Swept-up shells versus perturbed MHD disk wind

Astronomy and Astrophysics, Dec 1, 2022

Context. The origin of outflows and their exact impact on disk evolution and planet formation rem... more Context. The origin of outflows and their exact impact on disk evolution and planet formation remain crucial open questions. DG Tau B is a Class I protostar associated with a rotating conical CO outflow and a structured disk. Hence it is an ideal target to study these questions. Aims. We aim to characterize the morphology and kinematics of the DG Tau B outflow in order to elucidate its origin and potential impact on the disk. Methods. Our analysis is based on Atacama Large Millimeter Array (ALMA) 12CO(2–1) observations of DG Tau B at 0.15″ (20 au) angular resolution. We developed a tomographic method to recover 2D (R,Z) maps of vertical velocity VZ and specific angular momentum j = R × Vϕ. We created synthetic data cubes for parametric models of wind-driven shells and disk winds, which we fit to the observed channel maps. Results. Tomographic analysis of the bright inner conical outflow shows that both VZ and j remain roughly constant along conical surfaces, defining a shear-like structure. We characterize three different types of substructures in this outflow (arches, fingers, and cusps) with apparent acceleration. Wind-driven shell models with a Hubble law fail to explain these substructures. In contrast, both the morphology and kinematics of the conical flow can be explained by a steady conical magnetohydrodynamic (MHD) disk wind with foot-point radii r0 ≃ 0.7–3.4 au, a small magnetic level arm parameter (λ ≤ 1.6), and quasi periodic brightness enhancements. These might be caused by the impact of jet bow shocks, source orbital motion caused by a 25 MJ companion at 50 au, or disk density perturbations accreting through the wind launching region. The large CO wind mass flux (four times the accretion rate onto the central star) can also be explained if the MHD disk wind removes most of the angular momentum required for steady disk accretion. Conclusions. Our results provide the strongest evidence so far for the presence of massive MHD disk winds in Class I sources with residual infall, and they suggest that the initial stages of planet formation take place in a highly dynamic environment.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Role of Gas in the Merging of Massive Black Holes in Galactic Nuclei

Springer eBooks, Feb 1, 2006

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Research paper thumbnail of ALMA reveals a large structured disk and nested rotating outflows in DG Tauri B

Astronomy and Astrophysics, Feb 1, 2020

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Research paper thumbnail of The HH30 edge-on T Tauri star

Astronomy and Astrophysics, Oct 1, 2018

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Research paper thumbnail of A Collimated Stellar Wind Emanating from a Massive Protostar

Springer eBooks, 2004

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Research paper thumbnail of A three-dimensional chemical simulation with irregular density distributions of L1544

Monthly Notices of the Royal Astronomical Society, Mar 2, 2023

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Research paper thumbnail of Models of Rotating Infall for the B335 Protostar

arXiv (Cornell University), Dec 7, 2022

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Research paper thumbnail of CO(2-->1) and 13CO(1-->0) emission from luminous southern infrared galaxies

Astronomy and Astrophysics, Oct 1, 1993

, We observed, using the SEST 15-m telescope, the CO(2-1) line emission toward eight highly lumin... more , We observed, using the SEST 15-m telescope, the CO(2-1) line emission toward eight highly luminous infrared galaxies of the southern hemisphere which were previously detected in the CO(1-0) transition. While the shapes of the (2 - 1) and (1 - 0) line profiles (taken with angular resolutions of 24" and 45", respectively) are remarkably similar, the ratios of observed peak main-beam radiation temperatures vary between 1.2 and 2.6. The derived (2-1)/(1-0) ratios of velocity integrated brightness temperature range between 0.33 and 0.77, indicating that the physical conditions of the molecular gas varies from source to source. Assuming that the kinetic temperature of the molecular gas is similar to the temperature derived for the dust (~30-40 K), the low values of the integrated line ratios imply that the CO is subthermally excited and that the bulk of the emission arises from regions of moderate H_2_ density, between 100 and 500 cm^-3^. We find that the use of the Galactic CO-H_2_ conversion factor is appropriate, to within a factor of 1.5, to estimate the molecular mass in this type of galaxies. We also observed four of these galaxies in the ^13^CO(1-0) transition and one in the ^13^CO(2-1) line. The ^12^CO(1-0)/^13^CO(1-0) velocity integrated brightness temperature ratios range from 9 to 27. The largest values, about 5 times greater than the average ratio observed for molecular clouds in the Milky Way disk, are exhibited by the most luminous IR galaxies. They can be explained if molecular clouds in mergers have low and moderate optical depths in ^13^CO and ^12^CO, respectively.

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Research paper thumbnail of Formation of formaldehyde through methanol-ice-mantle (CH<sub>3</sub>OH)<sub>10</sub> bombardment by OH<sup>+</sup> cation

Astronomy and Astrophysics, Jun 1, 2021

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Research paper thumbnail of The Evolution of Protostellar Outflow Cavities, Kinematics, and Angular Distribution of Momentum and Energy in Orion A: Evidence for Dynamical Cores

arXiv (Cornell University), Feb 6, 2023

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Co Survey in Planet-Forming Disks: Characterizing the Gas Content in the Epoch of Planet Formation

The Astronomical Journal, Jul 31, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Outflow Entrainment and Feedback: A Case Study with HH46/47 Molecular Outflow

Bookmarks Related papers MentionsView impact

Research paper thumbnail of ALMA Reveals Sequential High-mass Star Formation in the G9.62+0.19 Complex

The Astrophysical Journal, Oct 26, 2017

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