arXiv subjects

Mario Giuseppe Guarcello

Publications and source records attributed to Mario Giuseppe Guarcello.

5 recordsLinked to original sources

arXiv2026

SHARPing accretion and outflows in young stellar objects in star forming regions of the outer Galaxy and beyond

As part of the science book of SHARP, we present here the science case of star-disk interaction of low-mass (\Mstar$\leq$2\Msun) young stellar objects (YSOs), in low-metallicity (Z$<$ 0.2 \Zsun) star forming regions (SFRs) and supermassive star clusters, using the SHARP instrument mounted on the ESO-ELT. Extreme adaptive optics (AOs), with a spatial resolution a factor $\sim$3 better than JWST, as well as sensitive multiplexing capabilities, uniquely offered by SHARP, are essential to efficiently survey the whole area of low-Z SFRs and massive clusters in the outer Milky Way (MW) Galaxy and in the Magellanic Clouds (MCs). Using the SHARP exposure time calculator (ETC) we demonstrate that SHARP can achieve the required signal-to-noise, both for the continuum and emission lines, to investigate accretion and outflows in YSOs in distant (d$>$5\,kpc) SFRs, including those relatively embedded. SHARP will be able to observe very faint YSOs ($H\sim$\,24\,mag), allowing us extending studies to very low-mass YSOs in distant SFRs. The performance of SHARP in terms of sensitivity and spatial resolution in the NIR will provide significant insights into the evolution of protoplanetary disks in low-metallicity and massive environments: studies of accretion, jets/winds and photo-evaporation processes, down to the very low-mass ($\sim$0.2\,\Msun) regime in the MCs, and down to substellar YSOs in SFRs of the outer MW Galaxy (d\,$\lesssim$\,10\,kpc), will be possible. SHARP will also be able to observe jets/outflows in targets that are several magnitudes fainter than those reachable with current instruments, and will facilitate studies in low metallicity environments of wide binaries and multiple systems, with separations of $\sim$1600\,au, at a distance $\sim$50\,kpc scale, and of $\sim$150\,au, in regions of the outer MW Galaxy (d $\sim$10\,kpc).

astro-ph.IM↗

arXiv2025

Toward the time-domain spectroscopic study of the dynamic life of stars: from accretion to magnetic activity

Stars and planets can be seen as the second fundamental building blocks of baryons in the universe (only second to the dust and gas in molecular clouds). Their formation involves dust grain growth of many orders of magnitude and a myriad of processes operating at time scales from a few tens to millions of years. Thus, investigating the formation and evolution of young stellar objects (YSOs) is of great importance in modern astronomy. Addressing this goal requires overcoming long-standing challenges in characterizing multifaceted phenomena that span a broad range of astrophysical processes (from protoplanetary disk evolution and planet formation to accretion dynamics and transient stellar events). Also, YSOs are complex systems that consist of several components: a central forming object, surrounded by a medium or disk from which the accretion process is at work, supersonic ejection of plasma in the form of collimated bipolar jets (which interact with the ambient medium through which they propagate) and all these components emit in a wide range of wavelengths. A facility capable of simultaneously tackling these diverse questions must deliver long-term, high-cadence spectroscopic monitoring of YSOs over time spans of at least a decade; especially because accretion/ejection processes in YSOs are characterized by a wide range of temporal variability: from short-term (hours-days) to long-term (months-years) variability due to rotation, accretion, magnetic activity, etc. Such a mission demands a spectroscopic platform considering a solid time-domain astronomy framework, providing repeated observations over wide fields and supporting multiple cadence strategies tailored to distinct scientific objectives.

astro-ph.IM↗

arXiv2025

The JWST Galactic Center Survey -- A White Paper

The inner hundred parsecs of the Milky Way hosts the nearest supermassive black hole, largest reservoir of dense gas, greatest stellar density, hundreds of massive main and post main sequence stars, and the highest volume density of supernovae in the Galaxy. As the nearest environment in which it is possible to simultaneously observe many of the extreme processes shaping the Universe, it is one of the most well-studied regions in astrophysics. Due to its proximity, we can study the center of our Galaxy on scales down to a few hundred AU, a hundred times better than in similar Local Group galaxies and thousands of times better than in the nearest active galaxies. The Galactic Center (GC) is therefore of outstanding astrophysical interest. However, in spite of intense observational work over the past decades, there are still fundamental things unknown about the GC. JWST has the unique capability to provide us with the necessary, game-changing data. In this White Paper, we advocate for a JWST NIRCam survey that aims at solving central questions, that we have identified as a community: i) the 3D structure and kinematics of gas and stars; ii) ancient star formation and its relation with the overall history of the Milky Way, as well as recent star formation and its implications for the overall energetics of our galaxy's nucleus; and iii) the (non-)universality of star formation and the stellar initial mass function. We advocate for a large-area, multi-epoch, multi-wavelength NIRCam survey of the inner 100\,pc of the Galaxy in the form of a Treasury GO JWST Large Program that is open to the community. We describe how this survey will derive the physical and kinematic properties of ~10,000,000 stars, how this will solve the key unknowns and provide a valuable resource for the community with long-lasting legacy value.

astro-ph.GA↗

arXiv2024

The Wide-field Spectroscopic Telescope (WST) Science White Paper

The Wide-field Spectroscopic Telescope (WST) is proposed as a new facility dedicated to the efficient delivery of spectroscopic surveys. This white paper summarises the initial concept as well as the corresponding science cases. WST will feature simultaneous operation of a large field-of-view (3 sq. degree), a high multiplex (20,000) multi-object spectrograph (MOS) and a giant 3x3 sq. arcmin integral field spectrograph (IFS). In scientific capability these requirements place WST far ahead of existing and planned facilities. Given the current investment in deep imaging surveys and noting the diagnostic power of spectroscopy, WST will fill a crucial gap in astronomical capability and work synergistically with future ground and space-based facilities. This white paper shows that WST can address outstanding scientific questions in the areas of cosmology; galaxy assembly, evolution, and enrichment, including our own Milky Way; origin of stars and planets; time domain and multi-messenger astrophysics. WST's uniquely rich dataset will deliver unforeseen discoveries in many of these areas. The WST Science Team (already including more than 500 scientists worldwide) is open to the all astronomical community. To register in the WST Science Team please visit https://www.wstelescope.com/for-scientists/participate

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arXiv2021

Exploring the link between star and planet formation with Ariel

The goal of the Ariel space mission is to observe a large and diversified population of transiting planets around a range of host star types to collect information on their atmospheric composition. The planetary bulk and atmospheric compositions bear the marks of the way the planets formed: Ariel's observations will therefore provide an unprecedented wealth of data to advance our understanding of planet formation in our Galaxy. A number of environmental and evolutionary factors, however, can affect the final atmospheric composition. Here we provide a concise overview of which factors and effects of the star and planet formation processes can shape the atmospheric compositions that will be observed by Ariel, and highlight how Ariel's characteristics make this mission optimally suited to address this very complex problem.

astro-ph.EP↗