Publications (80)
New brown dwarfs in the south part of the Upper Scorpius Association
P. Dawson, A. Scholz, T. P. Ray
This paper presents the results of a search for brown dwarfs in the Upper Scorpius Association using data from the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Cluster Survey.…
The GRAVITY Young Stellar Object survey IV. The CO overtone emission in 51 Oph at sub-au scales
GRAVITY Collaboration, M. Koutoulaki, R. Garcia Lopez +69
51 Oph is a Herbig Ae/Be star that exhibits strong near-infrared CO ro-vibrational emission at 2.3 micron, most likely originating in the innermost regions of a circumstellar disc.…
JWST Observations of Young protoStars (JOYS+): Detection of icy complex organic molecules and ions. I. CH, SO, HCOO, OCN, HCO, HCOOH, CHCHOH, CHCHO, CHOCHO, CHCOOH
W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler +23
Complex organic molecules (COMs) detected in the gas phase are thought to be mostly formed on icy grains, but no unambiguous detection of icy COMs larger than CH3OH has been report…
Low-frequency monitoring of flare star binary CR Draconis: Long-term electron-cyclotron maser emission
J. R. Callingham, B. J. S. Pope, A. D. Feinstein +12
Recently detected coherent low-frequency radio emission from M dwarf systems shares phenomenological similarities with emission produced by magnetospheric processes from the gas gi…
The Spatial Distribution of Star Formation in the Solar Neighbourhood: Do all stars form in clusters?
E. Bressert, N. Bastian, R. Gutermuth +12
We present a global study of low mass, young stellar object (YSO) surface densities in nearby (< 500 pc) star forming regions based on a comprehensive collection of Spitzer Space T…
Peculiar radioX-ray relationship in active stars
H. K. Vedantham, J. R. Callingham, T. W. Shimwell +5
The empirical relationship between the non-thermal 5GHz radio luminosity and the soft X-ray luminosity of active stellar coronae, canonically called the Güdel-Benz relationship (G…
Magnetic fields and Star Formation around HII regions: The S235 complex
R. Devaraj, D. P. Clemens, L. K. Dewangan +3
Magnetic fields are ubiquitous and essential in star formation. In particular, their role in regulating formation of stars across diverse environments like HII regions needs to be…
Classical T Tauri-like Outflow Activity in the Brown Dwarf Mass Regime
E. T. Whelan, T. P. Ray, L. Podio +2
Over the last number of years spectroscopic studies have strongly supported the assertion that protostellar accretion and outflow activity persists to the lowest masses. In this pa…
POISSON project - II - A multi-wavelength spectroscopic and photometric survey of young protostars in L 1641
A. Caratti o Garatti, R. Garcia Lopez, S. Antoniucci +6
Characterising stellar and circumstellar properties of embedded young stellar objects (YSOs) is mandatory for understanding the early stages of the stellar evolution. This task req…
Detection of a warm molecular wind in DG Tauri
M. Takami, A. Chrysostomou, T. P. Ray +5
We detect near-infrared H2 emission in DG Tau using the Infrared Camera and Spectrograph (IRCS) on the 8.2-m SUBARU telescope. The spectra obtained along the jet axis show that the…
New brown dwarf disks in Upper Scorpius observed with WISE
P. Dawson, A. Scholz, T. P. Ray +5
We present a census of the disk population for UKIDSS selected brown dwarfs in the 5-10 Myr old Upper Scorpius OB association. For 116 objects originally identified in UKIDSS, the…
A measure of the size of the magnetospheric accretion region in TW Hydrae
R. Garcia Lopez, A. Natta, A. Caratti o Garatti +69
Stars form by accreting material from their surrounding disks. There is a consensus that matter flowing through the disk is channelled onto the stellar surface by the stellar magne…
Accretion-ejection connection in the young brown dwarf candidate ISO-Cha1 217
E. T. Whelan, J. M. Alcala, F. Bacciotti +7
As the number of observed brown dwarf outflows is growing it is important to investigate how these outflows compare to the well studied jets from young stellar objects. A key point…
HCN and C2H2 in the atmosphere of a T8.5+T9 brown dwarf binary
Elisabeth C. Matthews, Paul Mollière, Helena Kühnle +22
T-type brown dwarfs present an opportunity to explore atmospheres teeming with molecules such as H2O, CH4 and NH3, which exhibit a wealth of absorption features in the mid-infrared…
JOYS: Disentangling the warm and cold material in the high-mass IRAS 23385+6053 cluster
C. Gieser, H. Beuther, E. F. van Dishoeck +20
(abridged) We study and compare the warm (>100 K) and cold (<100 K) material toward the high-mass star-forming region IRAS 23385+6053 (IRAS 23385 hereafter) combining high angular…
Atomic jets from class 0 sources detected by Spitzer: the case of L1448-C
O. Dionatos, B. Nisini, R. Garcia Lopez +5
We present Spitzer-IRS spectra obtained along the molecular jet from the Class 0 source L1448-C (or L1448-mm). Atomic lines from the fundamental transitions of [FeII], [SiII] and […
AO Assisted Near-IR Spectroscopy of SVS 13 and its Jet
C. J. Davis, B. Nisini, M. Takami +5
We present long-slit H- and K-band spectroscopy of the low-mass outflow source SVS 13, obtained with the adaptive-optics assisted imager-spectrometer NACO on the VLT. With a spatia…
Proper Motion Studies of Outflows from Classical T Tauri Stars
F. McGroarty, T. P. Ray, D. Froebrich
In a previous paper (McGroarty & Ray 2004, 420, 975) we examined the environment of a number of evolved low-mass young stars, i.e. Classical T Tauri Stars, to see if they are capab…
Jets and Outflows From Star to Cloud: Observations Confront Theory
A. Frank, T. P. Ray, S. Cabrit +10
In this review we focus on the role jets and outflows play in the star and planet formation process. Our essential question can be posed as follows: are jets/outflows merely an epi…
Constraining the nature of DG Tau A's thermal and non-thermal radio emission
S. J. D. Purser, R. E. Ainsworth, T. P. Ray +3
DG Tau A, a class-II young stellar object (YSO) displays both thermal, and non-thermal, radio emission associated with its bipolar jet. To investigate the nature of this emission,…
Discovery of a Bipolar Outflow from 2MASSW J1207334-393254, A 24 Jupiter Mass Brown Dwarf
E. T. Whelan, T. P. Ray, S. Randich +5
The 24 M Jupiter mass brown dwarf 2MASS1207-3932 has for some time been known to show clear signs of classical T Tauri-like accretion. Through analysis of its oxygen forbidden emis…
PROJECT-J: JWST observations of HH46~IRS and its outflow. Overview and first results
B. Nisini, M. G. Navarro, T. Giannini +23
We present the first results of the JWST program PROJECT-J (PROtostellar JEts Cradle Tested with JWST ), designed to study the Class I source HH46 IRS and its outflow through NIRSp…
Detection of coherent low-frequency radio bursts from weak-line TTauri stars
A. Feeney-Johansson, S. J. D. Purser, T. P. Ray +7
In recent years, thanks to new facilities such as LOFAR capable of sensitive observations, much work has been done on the detection of stellar radio emission at low frequencies. Su…
Tracing jet emission at the base of a high-mass YSO. First AMBER/VLTI observations of the Brγemission in IRAS 13481-6124
A. Caratti o Garatti, B. Stecklum, G. Weigelt +9
To probe the circumstellar environment of IRAS 13481-6124, a 20 M_sun high-mass young stellar object (HMYSO) with a parsec-scale jet and accretion disc, we investigate the origin o…
The SONYC survey: Towards a complete census of brown dwarfs in star forming regions
K. Muzic, A. Scholz, V. C. Geers +4
SONYC, short for "Substellar Objects in Nearby Young Clusters", is a survey program to provide a census of the substellar population in nearby star forming regions. We have conduct…
Classical T Tauri stars as sources of parsec-scale optical outflows
F. McGroarty, T. P. Ray
Previous studies of young stellar objects (YSOs) have uncovered a number of associated parsec-scale optical outflows, the majority of which are driven by low-mass, embedded Class I…
Numerical Simulations of the Kelvin-Helmholtz instability in radiatively cooled jets
T. P. Downes, T. P. Ray
We present the results of simulations of the development of the Kelvin-Helmholtz (KH) instability in a cooled, slab symmetric system. The parameters were chosen to approximate the…
The Mid-Infrared Instrument for the James Webb Space Telescope, III: MIRIM, The MIRI Imager
P. Bouchet, M. Garcia-Marin, P. -O. Lagage +34
In this article, we describe the MIRI Imager module (MIRIM), which provides broad-band imaging in the 5 - 27 microns wavelength range for the James Webb Space Telescope. The imager…
MICONIC: The spatial relationship between star formation and the AGN in Centaurus A revealed by JWST/MIRI
O. C. Jones, M. L. Jones, D. Dicken +21
Centaurus A (Cen A), the nearest active radio galaxy, hosts a warped dust disc formed in a gas-rich merger. We present JWST/MIRI imaging in three filters, F560W, F770W, and F1130W,…
Near-Infrared Polarimetry and H emission toward Massive Young Stars: Discovery of a Bipolar Outflow associated to S235 e2s3
R. Devaraj, A. Caratti o Garatti, L. K. Dewangan +3
We present a near-infrared band polarimetric study toward the S235 e2s3 protostar, obtained using the POLICAN instrument on the 2.1m OAGH telescope. The images reveal a bipolar…
Diverse stages of star formation in the IRAS 18162-2048 region. Emergence of UV Feedback
R. Fedriani, G. Anglada, A. Caratti o Garatti +15
Methods: We obtained adaptive optics-assisted integral field spectroscopy in the near-infrared (IR) band () with VLT/SINFONI, complemented by VLA X and…
Investigating the asymmetry of young stellar outflows: Combined MUSE-X-shooter study of the Th 28 jet
A. Murphy, E. T. Whelan, F. Bacciotti +7
Characterising stellar jet asymmetries is key to setting robust constraints on jet launching models and improving our understanding of the underlying mechanisms behind jet launchin…
The wind and the magnetospheric accretion onto the T Tauri star S Coronae Australis at sub-au resolution
R. Garcia Lopez, K. Perraut, A. Caratti o Garatti +70
To investigate the inner regions of protoplanetary disks, we performed near-infrared interferometric observations of the classical TTauri binary system S CrA. We present the first…
High-uniformity TiN/Ti/TiN multilayers for the development of Microwave Kinetic Inductance Detector
Mario De Lucia, E. Baldwin, G. Ulbricht +4
Microwave Kinetic Inductance Detectors (MKIDs) are a class of superconducting cryogenic detectors that simultaneously exhibit energy resolution, time resolution and spatial resolut…
Unlocking accretion rate diagnostics for high-mass protostars using JWST/MIRI HI lines
S. D. Reyes-Reyes, H. Beuther, E. F. van Dishoeck +14
While many aspects of high-mass star formation have been investigated, the accretion onto the central protostars is one of the most fundamental but less explored physical propertie…
MINDS: JWST/NIRCam imaging of the protoplanetary disk PDS 70
V. Christiaens, M. Samland, Th. Henning +28
Context. Two protoplanets have recently been discovered within the PDS 70 protoplanetary disk. JWST/NIRCam offers a unique opportunity to characterize them and their birth environm…
First Results from the REAL-time Transient Acquisition backend (REALTA) at the Irish LOFAR station
P. C. Murphy, P. Callanan, J. McCauley +27
Modern radio interferometers such as the LOw Frequency ARray (LOFAR) are capable of producing data at hundreds of gigabits to terabits per second. This high data rate makes the ana…
JWST/MIRI observations of the young TWA 27 system: hydrocarbon disk chemistry, silicate clouds, evidence for a CPD
P. Patapis, M. Morales-Calderón, A. M. Arabhavi +39
The Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) enables the characterisation of young self-luminous gas giants at previously inaccessible wavelengths, r…
JWST MIRI Imager Observations of Supernova SN 1987A
P. Bouchet, R. Gastaud, A. Coulais +31
There exist very few mid-infrared (IR) observations of supernovae (SNe) in general. Therefore, SN 1987A, the closest visible SN in 400 years, gives us the opportunity to explore th…
A Global Jet/Circulation Model for Young Stars
T. Lery, R. N. Henriksen, J. D. Fiege +3
Powerful, highly collimated jets, surrounded by bipolar molecular outflows, are commonly observed near Young Stellar Objects (YSOs). In the usual theoretical picture of star format…
HST/STIS Spectroscopy of the Optical Outflow from DG Tau: Indications for Rotation in the Initial Jet Channel
F. Bacciotti, T. P. Ray, R. Mundt +2
We have carried out a kinematical, high angular resolution (~ 0".1) study of the jet from DG Tau within 0."5 from the source (or 110 AU along this flow). We analysed line profiles…
Abundant hydrocarbons in the disk around a very-low-mass star
A. M. Arabhavi, I. Kamp, Th. Henning +40
Very low-mass stars (those <0.3 solar masses) host orbiting terrestrial planets more frequently than other types of stars, but the compositions of those planets are largely unknown…
The circumstellar environment of HD50138 revealed by VLTI/AMBER at high angular resolution
M. Koutoulaki, R. Garcia Lopez, A. Natta +4
HD50138 is a Herbig B[e] star with a circumstellar disc detected at IR and mm wavelength. Its brightness makes it a good candidate for NIR interferometry observations. We aim to re…
The outburst of an embedded low-mass YSO in L1641
A. Caratti o Garatti, R. Garcia Lopez, A. Scholz +6
Strong outbursts in very young and embedded protostars are rare and not yet fully understood. They are believed to originate from an increase of the mass accretion rate onto the so…
A high-resolution radio study of the L1551 IRS 5 and L1551 NE jets
A. Feeney-Johansson, S. J. D. Purser, T. P. Ray +10
Using observations with e-MERLIN and the VLA, together with archival data from ALMA, we obtain high-resolution radio images of two binary YSOs: L1551 IRS 5 and L1551 NE, covering a…
The GRAVITY young stellar object survey. II. First spatially resolved observations of the CO bandhead emission in a high-mass YSO
GRAVITY Collaboration, A. Caratti o Garatti, R. Fedriani +50
The inner regions of the discs of high-mass young stellar objects (HMYSOs) are still poorly known due to the small angular scales and the high visual extinction involved. We deploy…
Information content of JWST transmission spectroscopy of the exoplanet HAT-P-12b from the optical to the mid-infrared
L. Heinke, M. Min, J. Bouwman +18
The James Webb Space Telescope (JWST) provides low- to medium-resolution spectra with unprecedented precision and broad near- to mid-infrared wavelength coverage, enabling detailed…
Jets from Young Stars
T. P. Ray, J. Ferreira
Jets are ubiquitous in the Universe and, as demonstrated in this volume, are seen from a large number of astrophysical objects. For a number of reasons, in particular their proximi…
Subaru IR Echelle Spectroscopy of Herbig-Haro Driving Sources I. H_2 and [Fe II] Emission
M. Takami, A. Chrysostomou, T. P. Ray +6
We present infrared echelle spectroscopy of three Herbig-Haro (HH) driving sources (SVS 13, B5-IRS 1 and HH 34 IRS) using Subaru-IRCS. The large diameter of the telescope and wide…
Near Infrared Spectroscopy of Young Brown Dwarfs in Upper Scorpius
P. Dawson, A. Scholz, T. P. Ray +3
Spectroscopic follow-up is a pre-requisite for studies of the formation and early evolution of brown dwarfs. Here we present IRTF/SpeX near-infrared spectroscopy of 30 candidate me…
Ejecta, Rings, and Dust in SN 1987A with JWST MIRI/MRS
O. C. Jones, P. J. Kavanagh, M. J. Barlow +31
Supernova (SN) 1987A is the nearest supernova in 400 years. Using the {\em JWST} MIRI Medium Resolution Spectrograph, we spatially resolved the ejecta, equatorial ring (ER) a…
Physical Structure and Dust Reprocessing in a sample of HH Jets
L. Podio, S. Medves, F. Bacciotti +2
We investigate the physical structure and dust reprocessing in the shocks along the beam of a number of classical Herbig-Haro jets in the Orion and Lupus molecular cloud. Spectral…
JOYS: JWST MIRI/MRS spectra of the inner 500 au region of the L1527 IRS bipolar outflow
R. Devaraj, E. F. van Dishoeck, T. P. Ray +12
This study characterized the physical and kinematic properties within the innermost 500 au region of the L1527 bipolar outflow, a class 0/I low-mass protostar using JWST MIRI/MRS s…
Detection of CO, CO, and HO in the atmosphere of the warm sub-Saturn HAT-P-12b
N. Crouzet, B. Edwards, T. Konings +29
The chemical composition of warm gas giant exoplanet atmospheres (with Teq < 1000 K) is not well known due to the lack of observational constraints. HAT-P-12 b is a warm, sub-Satur…
Searching for Brown Dwarf Outflows
E. T. Whelan, T. P. Ray, F. Bacciotti +2
As outflow activity in low mass protostars is strongly connected to ac- cretion it is reasonable to expect accreting brown dwarfs to also be driving out- flows. In the last three y…
Disk-mediated accretion burst in a high-mass young stellar object
A. Caratti o Garatti, B. Stecklum, R. Garcia Lopez +13
Solar-mass stars form via circumstellar disk accretion (disk-mediated accretion). Recent findings indicate that this process is likely episodic in the form of accretion bursts, pos…
Water depletion and 15NH3 in the atmosphere of the coldest brown dwarf observed with JWST/MIRI
H. Kühnle, P. Patapis, P. Mollière +21
With a temperature of K WISE0855 is the coldest brown dwarf observed so far. Using the James Webb Space Telescope (JWST) we obtained observations that allow us to charac…
A MUSE Spectro-imaging Study of the Th 28 Jet: Precession in the Inner Jet
A. Murphy, C. Dougados, E. T. Whelan +5
Context: Th 28 is a Classical T Tauri star in the Lupus 3 cloud which drives an extended bipolar jet. Previous studies of the inner jet identified signatures of rotation around the…
Paschen beta emission as a tracer of outflow activity from T-Tauri stars, as compared to Optical Forbidden emission
E. T. Whelan, T. P. Ray, C. J. Davis
The Paschen beta (1.2822 micron) emission line found in the near-infrared spectra of T-Tauri stars (TTSs) is believed to trace the accretion of material onto the central star. We p…
Large closed-field corona of WX UMa evidenced from radio observations
I. Davis, H. K. Vedantham, J. R. Callingham +5
The space-weather conditions that result from stellar winds significantly impact the habitability of exoplanets. The conditions can be calculated from first principles if the neces…
SPIRou: nIR velocimetry & spectropolarimetry at the CFHT
J. -F. Donati, D. Kouach, C. Moutou +63
This paper presents an overview of SPIRou, the new-generation near-infrared spectropolarimeter / precision velocimeter recently installed on the 3.6-m Canada-France-Hawaii Telescop…
JWST Observations of Young protoStars (JOYS): overview of program and early results
E. F. van Dishoeck, Å. Tychoniec, W. R. M. Rocha +34
The embedded phase is a crucial period in the development of a young star. Mid-IR observations, now possible with JWST with unprecedented sensitivity, spectral resolution and sharp…
The kinematic relationship between disk and jet in the DG Tauri system
L. Testi, F. Bacciotti, A. I. Sargent +2
We present high angular resolution millimeter wavelength continuum and 13CO(2-1) observations of the circumstellar disk surrounding the TTauri star DG Tauri. We show that the veloc…
Exploring the dimming event of RW Aur A through multi-epoch VLT/X-Shooter spectroscopy
M. Koutoulaki, S. Facchini, C. F. Manara +6
RW Aur A is a CTTS that has suddenly undergone three major dimming events since 2010. We aim to understand the dimming properties, examine accretion variability, and derive the phy…
On the transfer of momentum from stellar jets to molecular outflows
T. P. Downes, T. P. Ray
While it is generally thought that molecular outflows from young stellar objects (YSOs) are accelerated by underlying stellar winds or highly collimated jets, the actual mechanism…
Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate?
A. Chrysostomou, F. Bacciotti, B. Nisni +4
In this pilot study, we examine molecular jets from the embedded Class I sources, HH 26 and HH 72, to search, for the first time, for kinematic signatures of jet rotation from youn…
JWST Observations of Young protoStars (JOYS). Overview of gaseous molecular emission and absorption in low-mass protostars
M. L. van Gelder, L. Francis, E. F. van Dishoeck +17
The MIRI-MRS instrument onboard JWST allows for probing the molecular gas composition at mid-IR wavelengths at unprecedented resolution and sensitivity. It is important to study th…
V-LoTSS: The Circularly-Polarised LOFAR Two-metre Sky Survey
J. R. Callingham, T. W. Shimwell, H. K. Vedantham +44
We present the detection of 68 sources from the most sensitive radio survey in circular polarisation conducted to date. We use the second data release of the 144 MHz LOFAR Two-metr…
Parsec-scale jets driven by high-mass young stellar objects. Connecting the au- and the parsec-scale jet in IRAS 13481-6124
R. Fedriani, A. Caratti o Garatti, D. Coffey +6
Context: Protostellar jets in high-mass young stellar objects (HMYSOs) play a key role in the understanding of star formation and provide us with an excellent tool to study fundame…
Uncovering the Outflow Driven by the Brown Dwarf LS-RCr A1: H-alpha as a Tracer of Outflow Activity in Brown Dwarfs
E. T. Whelan, T. P. Ray, F. Bacciotti
It is now apparent that classical T Tauri-like outflows commonly accompany the formation of young brown dwarfs. To date two optical outflows have been discovered and results presen…
JWST Observations of Young protoStars (JOYS). HH 211: the textbook case of a protostellar jet and outflow
A. Caratti o Garatti, T. P. Ray, P. J. Kavanagh +22
We use the James Webb Space Telescope (JWST) and its Mid-Infrared Instrument (MIRI) (5-28 um), to study the embedded HH 211 flow. We map a 0.95'x0.22' region, covering the full ext…
Emission lines due to ionizing radiation from a compact object in the remnant of Supernova 1987A
C. Fransson, M. J. Barlow, P. J. Kavanagh +31
The nearby Supernova 1987A was accompanied by a burst of neutrino emission, which indicates that a compact object (a neutron star or black hole) was formed in the explosion. There…
Stellar cosmic rays as an important source of ionisation in protoplanetary disks: a disk mass dependent process
D. Rodgers-Lee, A. M. Taylor, T. P. Downes +1
We assess the ionising effect of low energy protostellar cosmic rays in protoplanetary disks around a young solar mass star for a wide range of disk parameters. We assume a source…
Measuring the ionisation fraction in a jet from a massive protostar
R. Fedriani, A. Caratti o Garatti, S. J. D. Purser +7
It is important to determine if massive stars form via disc accretion, like their low-mass counterparts. Theory and observation indicate that protostellar jets are a natural conseq…
The Mid-Infrared Instrument for JWST, II: Design and Build
G. S. Wright, David Wright, G. B. Goodson +70
The Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) provides measurements over the wavelength range 5 to 28.5 microns. MIRI has, within a single 'package',…
Water in the terrestrial planet-forming zone of the PDS 70 disk
G. Perotti, V. Christiaens, Th. Henning +42
Terrestrial and sub-Neptune planets are expected to form in the inner (AU) regions of protoplanetary disks. Water plays a key role in their formation, although it is yet uncl…
Physical properties of the jet from DG Tauri on sub-arcsecond scales with HST/STIS
L. Maurri, F. Bacciotti, L. Podio +5
We derive the physical properties at the base of the jet from DG Tau both along and across the flow and as a function of velocity. We analysed seven optical spectra of the DG Tau j…
A rich hydrocarbon chemistry and high C to O ratio in the inner disk around a very low-mass star
B. Tabone, G. Bettoni, E. F. van Dishoeck +43
Carbon is an essential element for life but how much can be delivered to young planets is still an open question. The chemical characterization of planet-forming disks is a crucial…
A Galactic Plane Relative Extinction Map from 2MASS
D. Froebrich, T. P. Ray, G. C. Murphy +1
We present three 14400 square degree relative extinction maps of the Galactic Plane (|b|<20degrees) obtained from 2MASS using accumulative star counts (Wolf diagrams). This method…
The Mid-Infrared Instrument for the James Webb Space Telescope I: Introduction
G. H. Rieke, G. S. Wright, T. Boeker +15
MIRI (the Mid-Infrared Instrument for the James Webb Space Telescope (JWST)) operates from 5 to 28.5 microns and combines over this range: 1.) unprecedented sensitivity levels; 2.)…