Jet-ISM interactions near the microquasars GRS 1758-258 and 1E 1740.7-2942

We present Atacama Large Millimeter/Sub-millimeter Array observations of the candidate jet-ISM interaction zones near the black hole X-ray binaries GRS 1758-258 and 1E 1740.7-2942. Using these data, we map the molecular line emission in the regions, detecting emission from the HCN [J = 1-0], HCO+ [J = 1-0], SiO [J = 2-1], CS [J = 2-1], 13CO [J = 1-0], C18O [J = 1-0], HNCO [J = 40,4-30,3], HNCO [J = 50,5-40,4], and CH3OH [J = 21,1-11,0] molecular transitions. Through examining the morphological, spectral, and kinematic properties of this emission, we identify molecular structures that may trace jet-driven cavities in the gas surrounding these systems. Our results from the GRS 1758-258 region in particular, are consistent with recent work, which postulated the presence of a jet-blown cocoon structure in deep radio continuum maps of the region. Using these newly discovered molecular structures as calorimeters, we estimate the time averaged jet power from these systems, finding (1.1-5.7) × 1036 erg s-1 over 0.12-0.31 Myr for GRS 1758-258 and (0.7-3.5) × 1037 erg s-1 over 0.10-0.26 Myr for 1E 1740.7-2942. Additionally, the spectral line characteristics of the detected emission place these molecular structures in the central molecular zone of our Galaxy, thereby constraining the distances to the black hole X-ray binaries to be 8.0 ± 1.0 kpc. Overall, our analysis solidifies the diagnostic capacity of molecular lines, and highlights how astro-chemistry can both identify jet-ISM interaction zones and probe jet feedback from Galactic X-ray binaries

Interstellar MHD Turbulence and Star Formation

This chapter reviews the nature of turbulence in the Galactic interstellar medium (ISM) and its connections to the star formation (SF) process. The ISM is turbulent, magnetized, self-gravitating, and is subject to heating and cooling processes that control its thermodynamic behavior. The turbulence in the warm and hot ionized components of the ISM appears to be trans- or subsonic, and thus to behave nearly incompressibly. However, the neutral warm and cold components are highly compressible, as a consequence of both thermal instability in the atomic gas and of moderately-to-strongly supersonic motions in the roughly isothermal cold atomic and molecular components. Within this context, we discuss: i) the production and statistical distribution of turbulent density fluctuations in both isothermal and polytropic media; ii) the nature of the clumps produced by thermal instability, noting that, contrary to classical ideas, they in general accrete mass from their environment; iii) the density-magnetic field correlation (or lack thereof) in turbulent density fluctuations, as a consequence of the superposition of the different wave modes in the turbulent flow; iv) the evolution of the mass-to-magnetic flux ratio (MFR) in density fluctuations as they are built up by dynamic compressions; v) the formation of cold, dense clouds aided by thermal instability; vi) the expectation that star-forming molecular clouds are likely to be undergoing global gravitational contraction, rather than being near equilibrium, and vii) the regulation of the star formation rate (SFR) in such gravitationally contracting clouds by stellar feedback which, rather than keeping the clouds from collapsing, evaporates and diperses them while they collapse.Comment: 43 pages. Invited chapter for the book "Magnetic Fields in Diffuse Media", edited by Elisabete de Gouveia dal Pino and Alex Lazarian. Revised as per referee's recommendation

PHANGS-ALMA data processing and pipeline

Instrumentatio

Shock Excited Molecules in NGC 1266 : ULIRG Conditions at the Center of a Bulge-dominated Galaxy

We investigate the far infrared (IR) spectrum of NGC 1266, a S0 galaxy that contains a massive reservoir of highly excited molecular gas. Using the Herschel Fourier Transform Spectrometer, we detect the 12CO ladder up to J = (13-12), [C I] and [N II] lines, and also strong water lines more characteristic of UltraLuminous IR Galaxies (ULIRGs). The 12CO line emission is modeled with a combination of a low-velocity C-shock and a photodissociation region. Shocks are required to produce the H2O and most of the high-J CO emission. Despite having an IR luminosity 30 times less than a typical ULIRG, the spectral characteristics and physical conditions of the interstellar medium of NGC 1266 closely resemble those of ULIRGs, which often harbor strong shocks and large-scale outflowsPeer reviewe

JWST reveals star formationãcrossã spiralãrm in M33

Young stellar objects (YSOs)ãre the gold standard for tracing star formation in galaxies but have been unobservable beyond the Milky Wayãnd Magellanic Clouds. But thatãll changed when the JWST was launched, which we use to identify YSOs in the Local Group galaxy M33, marking the first time that individual YSOs have been identifiedãt these large distances. We present Mid-Infrared Instrument (MIRI) imaging mosaicsãt 5.6ãnd 21 μm that co v erã significant portion of one of M33's spiralãrms that has existing panchromatic imaging from the Hubble Space Telescopeãnd deep Atacama Large Millimeter/submillimeter Array CO measurements. Using these MIRIãnd Hubble Space Telescope images, we identify point sources using the new DOLPHOT MIRI module. We identify 793 candidate YSOs from cuts based on colour, proximity to giant molecular clouds (GMCs),ãnd visual inspection. Similar to Milky Way GMCs, we find that higher mass GMCs contain more YSOsãnd YSO emission, which further show YSOs identify star formation better than most tracers that cannot capture this relationshipãt cloud scales. We find evidence of enhanced star formation efficiency in the southern spiralãrm by comparing the YSOs to the molecular gas mass. © 2023 The Author(s).Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Extreme jet ejections from the black hole X-ray binary V404 Cygni

We present simultaneous radio through sub-mm observations of the black hole X-ray binary (BHXB) V404 Cygni during the most active phase of its June 2015 outburst. Our 4 h long set of overlapping observations with the Very Large Array, the Sub-millimeter Array and the James Clerk Maxwell Telescope (SCUBA-2) covers eight different frequency bands (including the first detection of a BHXB jet at 666 GHz/450 μm), providing an unprecedented multifrequency view of the extraordinary flaring activity seen during this period of the outburst. In particular, we detect multiple rapidly evolving flares, which reach Jy-level fluxes across all of our frequency bands. With this rich data set, we performed detailed MCMC modelling of the repeated flaring events. Our custom model adapts the van der Laan synchrotron bubble model to include twin bi-polar ejections, propagating away from the black hole at bulk relativistic velocities, along a jet axis that is inclined to the line of sight. The emission predicted by our model accounts for projection effects, relativistic beaming and the geometric time delay between the approaching and receding ejecta in each ejection event. We find that a total of eight bi-polar, discrete jet ejection events can reproduce the emission that we observe in all of our frequency bands remarkably well. With our best-fitting model, we provide detailed probes of jet speed, structure, energetics and geometry. Our analysis demonstrates the paramount importance of the mm/sub-mm bands, which offer a unique, more detailed view of the jet than can be provided by radio frequencies alone