JOURNEY: Jets and Outflows Revealing the Nature and Evolution of massive YSOs
Project goal: improve our understanding of mass outflows during the formation of high-mass stars using observational probes on a variety of spatial length scales. Project JOURNEY.
Star Formation from Galactic Molecular Clouds to Starburst Galaxies
Our group focuses on the study of star formation, in particular the
formation of stars eight times or more massive than the Sun – commonly
called massive stars. We conduct observations at radio frequencies with
the most powerful radio telescopes available, including the Very Large Array (VLA) in New Mexico.
Observations at radio frequencies are necessary because stars form in very opaque clouds, and thus the very early phases of star formation can be only studied at low frequencies and not at, for example, optical wavelengths. Astrophysical research conducted at radio (meter to sub-mm) wavelengths is in the process of a revolution. The arrival of new and upgraded facilities will improve current capabilities by orders of magnitude in almost all desired characteristics, e.g., from sensitivity, such as the Jansky Very Large Array (VLA), to wavelength coverage, from the Long Wavelength Array (LWA) to the Atacama Large Millimeter/Submillimeter Array (ALMA). Research in astronomy, in particular in radio astronomy, is also experiencing a fundamental change due to the internet: observations using the most powerful radio telescopes can be done in remote mode without the need of traveling.
The research of our group may be divided in four broad areas:
Observations at radio frequencies are necessary because stars form in very opaque clouds, and thus the very early phases of star formation can be only studied at low frequencies and not at, for example, optical wavelengths. Astrophysical research conducted at radio (meter to sub-mm) wavelengths is in the process of a revolution. The arrival of new and upgraded facilities will improve current capabilities by orders of magnitude in almost all desired characteristics, e.g., from sensitivity, such as the Jansky Very Large Array (VLA), to wavelength coverage, from the Long Wavelength Array (LWA) to the Atacama Large Millimeter/Submillimeter Array (ALMA). Research in astronomy, in particular in radio astronomy, is also experiencing a fundamental change due to the internet: observations using the most powerful radio telescopes can be done in remote mode without the need of traveling.
The research of our group may be divided in four broad areas:
Identification
and High Angular Resolution Observations
– Identification of very early
sites of Massive Star Formation: Given the short time-scale for
the formation of massive stars, the identification of the youngest
objects is fundamental. We use a number of molecular probes, radio
continuum observations, and infrared data to identify very young regions of massive star formation.
– High Angular Resolution Studies: We are conducting several radio continuum and molecular line studies at sub-arcsecond angular resolution with the final goal of understanding the process of massive star formation.
– High Angular Resolution Studies: We are conducting several radio continuum and molecular line studies at sub-arcsecond angular resolution with the final goal of understanding the process of massive star formation.
Large
Scale Environment and the Milky Way
– Molecular Clumps and Envelopes:
Massive stars form in large molecular clouds. We explore the use of
different molecular transitions to study the kinematics of molecular
clumps and envelopes associated with star formation.
– Kinematic Distances to Star Forming Regions: Together with a number of collaborators, we have conducted several surveys using molecular and radio recombination lines to derive kinematic distances to massive star forming regions. Our efforts on this front continue, in particular evaluating the reliability of the methods used to resolve distance ambiguities and to explore the spiral structure of the Milky Way.
– Kinematic Distances to Star Forming Regions: Together with a number of collaborators, we have conducted several surveys using molecular and radio recombination lines to derive kinematic distances to massive star forming regions. Our efforts on this front continue, in particular evaluating the reliability of the methods used to resolve distance ambiguities and to explore the spiral structure of the Milky Way.
Non-thermal
Phenomena associated with Star Formation
– Formaldehyde Masers:
Our goal is to understand the physics of H2CO 6 cm maser emission. We
have conducted several surveys that have more than doubled the number
of known H2CO 6 cm maser regions in the Galaxy. Recent data are showing
that H2CO masers trace very young massive stellar objects, prior to the
formation of ultra-compact H II regions.
– Other Molecular Masers: Other more abundant maser species such as H2O and CH3OH masers are also used to explore the conditions where massive stars are forming, in particular as outflow tracers.
– Variability: We are particularly interested in two types of transients: 1. radio continuum outburst from low mass protostars (as a tool to explore the population of low mass protostars in massive star forming regions), and 2. variability of astrophysical masers, specifically correlated variability of different maser species and the astrophysics of periodic maser flares.
– Other Molecular Masers: Other more abundant maser species such as H2O and CH3OH masers are also used to explore the conditions where massive stars are forming, in particular as outflow tracers.
– Variability: We are particularly interested in two types of transients: 1. radio continuum outburst from low mass protostars (as a tool to explore the population of low mass protostars in massive star forming regions), and 2. variability of astrophysical masers, specifically correlated variability of different maser species and the astrophysics of periodic maser flares.
Extragalactic Environments
– Megamasers and Molecular
Absorption in Starburst Galaxies: We have conducted
observations of H2CO absorption and megamaser emission toward a number
of galaxies including starbursts. The goal of the project is to study
the molecular environment where the most profuse star formation takes
place.