Publications (41)
Chemistry in Disks. II. -- Poor molecular content of the AB Aur disk
Katharina Schreyer, Stéphane Guilloteau, Dmitry Semenov +9
We study the molecular content and chemistry of a circumstellar disk surrounding the Herbig Ae star AB Aur at (sub-)millimeter wavelengths. Our aim is to reconstruct the chemical h…
Detection of H emission from PZ Tel B using SPHERE/ZIMPOL
Arianna Musso Barcucci, Gabriele Cugno, Ralf Launhardt +7
H is a powerful tracer of accretion and chromospheric activity, which has been detected in the case of young brown dwarfs and even recently in planetary mass companions (e.g. P…
CID: Chemistry in disks VI.sulfur-bearing molecules in the protoplanetary disks surrounding LkCa15, MWC480, DM Tau, and GO Tau
Anne Dutrey, Valentine Wakelam, Yann Boehler +9
We study the content in S-bearing molecules of protoplanetary disks around low-mass stars. We used the new IRAM 30-m receiver EMIR to perform simultaneous observations of the $1_{1…
The Earliest Phases of Star Formation (EPoS): A Herschel Key Program - The precursors to high-mass stars and clusters
Sarah Ragan, Thomas Henning, Oliver Krause +14
(Abridged) We present an overview of the sample of high-mass star and cluster forming regions observed as part of the Earliest Phases of Star Formation (EPoS) Herschel Guaranteed T…
The seeds of star formation in the filamentary infrared-dark cloud G011.11-0.12
Thomas Henning, Hendrik Linz, Oliver Krause +5
Infrared-dark clouds (IRDCs) are the precursors to massive stars and stellar clusters. G011.11-0.12 is a well-studied filamentary IRDC, though, to date, the absence of far-infrared…
Evolution of Magnetic fields in Bok globules?
Sebastian Wolf, Ralf Launhardt, Thomas Henning
We study the influence and structure of the magnetic field in the early phases of low-mass star formation using polarization maps of Bok globules at a wavelength of 850micron, obta…
Magnetic field evolution in Bok globules
Sebastian Wolf, Ralf Launhardt, Thomas Henning
Using the Submillimeter Common-User Bolometer Array (SCUBA) at the James Clerk Maxwell Telescope (JCMT), we obtained submillimeter polarization maps of the Bok globules B335, CB230…
Rotational velocities of nearby young stars
Patrick Weise, Ralf Launhardt, Johny Setiawan +1
Stellar rotation is a crucial parameter driving stellar magnetism, activity and mixing of chemical elements. Furthermore, the evolution of stellar rotation is coupled to the evolut…
Chemistry in disks I - Deep search for NH in the protoplanetary disks around LkCa 15, MWC 480, and DM Tau
Anne Dutrey, Thomas Henning, Stephane Guilloteau +7
Aims: To constrain the ionization fraction in protoplanetary disks, we present new high-sensitivity interferometric observations of NH in three disks surrounding DM Tau, Lk…
ATCA and Spitzer Observations of the Binary Protostellar Systems CG30 and BHR71
Xuepeng Chen, Ralf Launhardt, Tyler L. Bourke +2
We present interferometric observations with resolution of ~3 arcsecs of the isolated, low-mass protostellar double cores CG30 and BHR71 in the N2$H+(1-0) line and at 3mm dust cont…
VLBI detection of nearby (< 100 pc) young stars: Pilot observations
Sergio A. Dzib, Laurent Loinard, Ralf Launhardt +1
To increase the number of sources with Very Long Baseline Interferometry (VLBI) astrometry available for comparison with the Gaia results, we have observed 31 young stars with rece…
Rotating Bullets from A Variable Protostar
Xuepeng Chen, Hector G. Arce, Qizhou Zhang +2
We present SMA CO(2-1) observations toward the protostellar jet driven by SVS13A, a variable protostar in the NGC1333 star-forming region. The SMA CO(2-1) images show an extremely…
Planet populations inferred from debris discs: insights from 178 debris systems in the ISPY, LEECH and LIStEN planet-hunting surveys
Tim D. Pearce, Ralf Launhardt, Robert Ostermann +11
We know little about the outermost exoplanets in planetary systems, because our detection methods are insensitive to moderate-mass planets on wide orbits. However, debris discs can…
Exoplanet search with astrometry
Ralf Launhardt
Searching for extrasolar planets by direct detection is extremely challenging for current instrumentation. Indirect methods, that measure the effect of a planet on its host star, a…
SMA CO(2-1) Observations of CG30: A Protostellar Binary System with a High-Velocity Quadrupolar Molecular Outflow
Xuepeng Chen, Tyler L. Bourke, Ralf Launhardt +1
We present interferometric observations in the 12CO (2-1) line and at 1.3 mm dust continuum of the low-mass protostellar binary system in the cometary globule CG30, using the Submi…
Detection of Complex Organic Molecules in Young Starless Core L1521E
Samantha Scibelli, Yancy Shirley, Anton Vasyunin +1
Determining the level of chemical complexity within dense starless and gravitationally bound prestellar cores is crucial for constructing chemical models, which subsequently constr…
ISPY -- NaCo Imaging Survey for Planets around Young stars. Discovery of an M dwarf in the gap between HD 193571 and its debris ring
Arianna Musso Barcucci, Ralf Launhardt, Grant M. Kennedy +19
Context. The interaction between low-mass companions and the debris discs they reside in is still not fully understood. A debris disc can evolve due to self-stirring, a process in…
IRAM-PdBI Observations of Binary Protostars I: The Hierarchical System SVS13 in NGC1333
Xuepeng Chen, Ralf Launhardt, Thomas Henning
We present millimeter interferometric observations of the young stellar object SVS13 in NCG1333 in the N2H+(1-0) line and at 1.4 and 3mm dust continuum, using the IRAM Plateau de B…
The JWST Early Release Science Program for the Direct Imaging & Spectroscopy of Exoplanetary Systems
Sasha Hinkley, Aarynn L. Carter, Shrishmoy Ray +83
The direct characterization of exoplanetary systems with high contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be…
Synthetic observations of first hydrostatic cores in collapsing low-mass dense cores. I. Spectral energy distributions and evolutionary sequence
Benoit Commercon, Ralf Launhardt, Cornelis P. Dullemond +1
The low-mass star formation evolutionary sequence is relatively well-defined both from observations and theoretical considerations. The first hydrostatic core is the first protoste…
Tests of achromatic phase shifters performed on the SYNAPSE test bench: a progress report
Pavel Gabor, Peter A. Schuller, Bruno Chazelas +16
The achromatic phase shifter (APS) is a component of the Bracewell nulling interferometer studied in preparation for future space missions (viz. Darwin/TPF-I) focusing on spectrosc…
HD 135344B: a young star has reached its rotational limit
André Müller, Mario van den Ancker, Ralf Launhardt +3
We search for periodic variations in the radial velocity of the young Herbig star HD 135344B with the aim to determine a rotation period. We analyzed 44 high-resolution optical spe…
The CARMENES search for exoplanets around M dwarfs: A low-mass planet in the temperate zone of the nearby K2-18
Paula Sarkis, Thomas Henning, Martin Kürster +22
K2-18 is a nearby M2.5 dwarf, located at 34 pc and hosting a transiting planet which was first discovered by the {\it K2} mission and later confirmed with {\it Spitzer Space Telesc…
Star formation in the Taurus filament L1495: From Dense Cores to Stars
Markus Schmalzl, Jouni Kainulainen, Sascha P. Quanz +6
We present a study of dense structures in the L1495 filament in the Taurus Molecular Cloud and examine its star-forming properties. In particular we construct a dust extinction map…
Synthetic observations of first hydrostatic cores in collapsing low-mass dense cores II. Simulated ALMA dust emission maps
Benoît Commerçon, François Levrier, Anaëlle J. Maury +2
First hydrostatic cores are predicted by theories of star formation, but their existence has never been demonstrated convincingly by (sub)millimeter observations. Furthermore, the…
Bayesian analysis of exoplanet and binary orbits
Tim Schulze-Hartung, Ralf Launhardt, Thomas Henning
We introduce BASE (Bayesian astrometric and spectroscopic exoplanet detection and characterisation tool), a novel program for the combined or separate Bayesian analysis of astromet…
G048.66-0.29: Physical State of an Isolated Site of Massive Star Formation
Jan Pitann, Hendrik Linz, Sarah Ragan +9
We present continuum observations of the infrared dark cloud (IRDC) G48.66-0.22 (G48) obtained with Herschel, Spitzer, and APEX, in addition to several molecular line observations.…
L1448 IRS2E: A candidate first hydrostatic core
Xuepeng Chen, Hector G. Arce, Qizhou Zhang +4
Intermediate between the prestellar and Class 0 protostellar phases, the first core is a quasi-equilibrium hydrostatic object with a short lifetime and an extremely low luminosity.…
Resolving the outer ring of HD 38206 using ALMA and constraining limits on planets in the system
Mark Booth, Michael Schulz, Alexander V. Krivov +3
HD 38206 is an A0V star in the Columba association, hosting a debris disc first discovered by IRAS. Further observations by Spitzer and Herschel showed that the disc has two compon…
Twenty-Five Years of Accretion onto the Classical T Tauri Star TW Hya
Gregory J. Herczeg, Yuguang Chen, Jean-Francois Donati +39
Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time…
Evolution of Cold Circumstellar Dust Around Solar-Type Stars
John M. Carpenter, Sebastian Wolf, Katharina Schreyer +2
We present submillimeter (CSO 350um) and millimeter (SEST 1.2 mm, OVRO 3 mm) photometry for 125 solar-type stars from the FEPS Spitzer Legacy program that have masses between ~0.5…
Intensity-Corrected Herschel Observations of Nearby Isolated Low-Mass Clouds
Sarah I. Sadavoy, Eric Keto, Tyler L. Bourke +8
We present intensity-corrected Herschel maps at 100 um, 160 um, 250 um, 350 um, and 500 um for 56 isolated low-mass clouds. We determine the zero-point corrections for Herschel PAC…
Dust SEDs in the era of Herschel and Planck: a Hierarchical Bayesian fitting technique
Brandon C. Kelly, Rahul Shetty, Amelia M. Stutz +3
We present a hierarchical Bayesian method for fitting infrared spectral energy distributions (SEDs) of dust emission to observed fluxes. Under the standard assumption of optically…
Pebbles in an Embedded Protostellar Disk: The Case of CB26
Chuan-Peng Zhang, Ralf Launhardt, Yao Liu +2
Planetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins. We study the physical str…
ISPY-NACO Imaging Survey for Planets around Young stars. The demographics of forming planets embedded in protoplanetary disks
Gabriele Cugno, Timothy D. Pearce, Ralf Launhardt +11
We present the statistical analysis of a subsample of 45 young stars surrounded by protoplanetary disks (PPDs). This is the largest imaging survey uniquely focused on PPDs to date.…
OVRO N2H+ Observations of Class 0 Protostars: Constraints on the Formation of Binary Stars
Xuepeng Chen, Ralf Launhardt, Thomas Henning
We present the results of an interferometric study of the N2H+(1--0) emission from nine nearby, isolated, low-mass protostellar cores, using the OVRO millimeter array. The main goa…
Unveiling wide-orbit companions to K-type stars in Sco-Cen with Gaia EDR3
Alexander J. Bohn, Christian Ginski, Matthew A. Kenworthy +12
Abbreviated. We aim to identify new low-mass companions to young stars using the astrometric measurements provided by the Gaia space mission and complementary VLT/SPHERE data. We i…
ESA Voyage 2050 White Paper: Detecting life outside our solar system with a large high-contrast-imaging mission
Ignas Snellen, Simon Albrecht, Guillem Anglada-Escude +64
In this white paper, we recommend the European Space Agency plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space tele…
SMA Observations of Class 0 Protostars: A High-Angular Resolution Survey of Protostellar Binary Systems
Xuepeng Chen, Hector G. Arce, Qizhou Zhang +8
We present high angular resolution 1.3 mm and 850 um dust continuum data obtained with the Submillimeter Array toward 33 Class 0 protostars in nearby clouds (distance < 500 pc), wh…
Forbidden emission lines in protostellar outflows and jets with MUSE
Lizxandra Flores-Rivera, Mario Flock, Nicolás Kurtovic +14
Forbidden emission lines in protoplanetary disks are a key diagnostic in studies of the evolution of the disk and the host star. We report spatially resolved emission lines, [OI] 6…
SMA and Spitzer Observations of Bok Glouble CB17: A Candidate First Hydrostatic Core?
Xuepeng Chen, Hector G. Arce, Michael M. Dunham +5
We present high angular resolution SMA and Spitzer observations toward the Bok globule CB17. SMA 1.3mm dust continuum images reveal within CB17 two sources with an angular separati…