Search Publications
The star-formation rates of 1.5 < z < 2.5 massive galaxies
Berta, S.; Magnelli, B.; Nordon, R. +31 more
The star formation rate (SFR) is a key parameter in the study of galaxy evolution. The accuracy of SFR measurements at z ~ 2 has been questioned following a disagreement between observations and theoretical models. The latter predict SFRs at this redshift that are typically a factor 4 or more lower than the measurements. We present star-formation …
Observations of Slow Electron Holes at a Magnetic Reconnection Site
André, M.; Vaivads, A.; Owen, C. J. +3 more
We report in situ observations of high-frequency electrostatic waves in the vicinity of a reconnection site in the Earth’s magnetotail. Two different types of waves are observed inside an ion-scale magnetic flux rope embedded in a reconnecting current sheet. Electron holes (weak double layers) produced by the Buneman instability are observed in th…
Star formation triggered by the Galactic H II region RCW 120. First results from the Herschel Space Observatory
Abergel, A.; Hill, T.; White, G. J. +10 more
Context. By means of different physical mechanisms, the expansion of H ii regions can promote the formation of new stars of all masses. RCW 120 is a nearby Galactic H ii region where triggered star formation occurs. This region is well-studied - there being a wealth of existing data - and is nearby. However, it is surrounded by dense regions for w…
Coronal properties of planet-bearing stars
Schmitt, J. H. M. M.; Robrade, J.; Poppenhaeger, K.
Context. Do extrasolar planets affect the activity of their host stars? Indications for chromospheric activity enhancement have been found for a handful of targets, but in the X-ray regime, conclusive observational evidence is still missing.
Aims: We want to establish a sound observational basis to confirm or reject major effects of Star-Plan…
Observation of Kink Instability During Small B5.0 Solar Flare on 2007 June 4
Srivastava, A. K.; Khodachenko, M. L.; Kumar, Pankaj +1 more
Using multi-wavelength observations of SOHO/MDI, SOT-Hinode/blue-continuum (4504 Å), G band (4305 Å), Ca II H (3968 Å), and TRACE 171 Å, we present the observational signature of a highly twisted magnetic loop in AR 10960 during the period 04:43 UT-04:52 UT on 2007 June 4. SOT-Hinode/blue-continuum (4504 Å) observations show that penumbral filamen…
Origin of the hot gas in low-mass protostars. Herschel-PACS spectroscopy of HH 46
de Graauw, Th.; Murphy, J. A.; Liseau, R. +62 more
Aims: “Water In Star-forming regions with Herschel” (WISH) is a Herschel key programme aimed at understanding the physical and chemical structure of young stellar objects (YSOs) with a focus on water and related species.
Methods: The low-mass protostar HH 46 was observed with the Photodetector Array Camera and Spectrometer (PACS) on the …
Properties of starspots on CoRoT-2
Alonso, R.; Barge, P.; Lanza, A. F. +1 more
Context. As a planet eclipses its parent star, a dark spot on the surface of the star may be occulted, causing a detectable variation in the light curve.
Aims: We study these light curve variations during transits and infer the physical characteristics of the stellar spots.
Methods: A total of 77 consecutive transit light curves of CoRoT…
The VLA-COSMOS Perspective on the Infrared-Radio Relation. I. New Constraints on Selection Biases and the Non-Evolution of the Infrared/Radio Properties of Star-Forming and Active Galactic Nucleus Galaxies at Intermediate and High Redshift
Aussel, H.; Le Floc'h, E.; Sanders, D. B. +18 more
VLA 1.4 GHz (σ~ 0.012 mJy) and MIPS 24 and 70 µm (σ~ 0.02 and 1.7 mJy, respectively) observations covering the 2 deg2 COSMOS field are combined with an extensive multiwavelength data set to study the evolution of the infrared (IR)-radio relation at intermediate and high redshift. With ~4500 sources—of which ~30% have spectroscopic…
Multiwavelength Observations of Small-scale Reconnection Events Triggered by Magnetic Flux Emergence in the Solar Atmosphere
Aulanier, G.; Guglielmino, S. L.; Bellot Rubio, L. R. +3 more
The interaction between emerging magnetic flux and the pre-existing ambient field has become a "hot" topic for both numerical simulations and high-resolution observations of the solar atmosphere. The appearance of brightenings and surges during episodes of flux emergence is believed to be a signature of magnetic reconnection processes. We present …
New Tests for Disruption Mechanisms of Star Clusters: The Large and Small Magellanic Clouds
Whitmore, Bradley C.; Fall, S. Michael; Chandar, Rupali
We compare the observed bivariate distribution of masses (M) and ages (τ) of star clusters in the Large Magellanic Cloud (LMC) with the predicted distributions g(M, τ) from three idealized models for the disruption of star clusters: (1) sudden mass-dependent disruption, (2) gradual mass-dependent disruption, and (3) gradual mass-independent disrup…