arXiv subjects

Ricardo Hernández Garnica

Publications and source records attributed to Ricardo Hernández Garnica.

3 recordsLinked to original sources

arXiv2026

Accurate proper motions of the protostellar system VLA1623-2417

We present a detailed astrometric analysis of the quadruple protostellar system VLA1623-2417, deriving accurate absolute proper motions for components A, B, and W, as well as, for the first time, individual motions for the compact binary components of A (Aa and Ab). Our study combines 37 archival interferometric observations from the Atacama Large Millimeter/submillimeter Array (ALMA) and the Karl G. Jansky Very Large Array (VLA) at centimeter and millimeter wavelengths, supplemented with additional data from the Submillimeter Array (SMA) and the Berkeley-Illinois-Maryland Association (BIMA) millimeter array taken from the literature. Together, these data provides time baselines of ~34.5 years for component B, ~32.5 years for component W, and ~11 years for the individual components Aa and Ab. The relative proper motions of Aa/Ab indicate significant orbital motions, but cover too small a fraction of the orbit to provide a reliable mass estimate. The relative proper motions of W with respect to components A and B indicate that their projected separations are decreasing at a rate of 1 to 2 km/s. These inward motions are inconsistent with scenarios in which component W has been dynamically ejected from the VLA1623-2417 system. Instead, we argue that W is either not bound to the A/B components or is moving on a highly inclined orbit.

astro-ph.GA↗

arXiv2025

FAUST XXX: Dust enhancement in the young binary L1551 IRS 5

Young binary stars with discs provide unique laboratories to study the earliest stages of planet formation in star-forming environments. The detection of substructure in discs around Class I protostars challenges current models of disc evolution, suggesting that planets may form earlier than previously expected ($<1$ Myr). In the context of the ALMA Large Program FAUST, we present observations of the circumbinary disc (CBD) around the young binary system L1551 IRS 5. The CBD exhibits two prominent over-densities in the continuum emission at the edge of the cavity, with the Northern over-density being about 20% brighter than the Southern one. By analysing the disc morphology and kinematics of L1551 IRS 5, we delineate dynamical constraints on the binary's orbital parameters. Additionally, we present 3D hydrodynamical models of the CBD to predict both the dust and the gas surface densities. Then, we compare the resulting synthetic observations with ALMA observations of the continuum emission at 1.3 mm and the C$^{18}$O line emission. Our analysis suggests that the density enhancements observed with ALMA in L1551 IRS 5 can be caused by interactions between the binary stars and the CBD, leading to dust concentration within the disc. We conclude that the observed over-density corresponds to a location where could potentially grow under favourable conditions.

astro-ph.SR↗

arXiv2025

Characterising the multiple protostellar system VLA 1623-2417 with JWST, ALMA and VLA: outflow origins, dust growth and an unsettled disk

Utilising JWST, ALMA and the VLA we present high angular resolution (0.06''- 0.42''), multi-wavelength (4 micron - 3cm) observations of the VLA 1623-2417 protostellar system to characterise the origin, morphology and, properties of the continuum emission. JWST observations at 4.4 micron reveal outflow cavities for VLA 1623 A and, for the first time, VLA 1623 B, as well as scattered light from the upper layers of the VLA 1623 W disk. We model the millimetre-centimetre spectral energy distributions to quantify the relative contributions of dust and ionised gas emission, calculate dust masses, and use spectral index maps to determine where optical depth hinders this analysis. In general, all objects appear to be optically thick down to ~90 GHz, show evidence for significant amounts (10's - 100's M_Earth) of large (>1 mm) dust grains, and are dominated by ionised gas emission for frequencies ~<15 GHz. In addition, we find evidence of unsettled millimetre dust in the inclined disk of VLA 1623 B possibly attributed to instabilities within the circumstellar disk, adding to the growing catalogue of unsettled Class 0/I disks. Our results represent some of the highest resolution observations possible with current instrumentation, particularly in the case of the VLA. However, our interpretation is still limited at low frequencies (~<22 GHz) and thus motivates the need for next-generation interferometers operating at centimetre wavelengths.

astro-ph.SR↗