Constraining the Jet Energetics of the Transient X-ray Binaries MAXI J1348-630 and MAXI J1820+070 through Calorimetry

TL;DR

This paper investigates jet–ISM feedback in transient black hole X-ray binaries using ALMA molecular line observations. By mapping tracers such as $^{13}$CO($J=1-0$), the authors identify a jet-driven cavity around MAXI J1348-630 and perform calorimetric jet-power estimates within a Kaiser self-similar framework, finding lifetime-averaged powers of order $Q_j\sim10^{25}$–$10^{28}$ erg s$^{-1}$ and total energy $E_{tot}\sim10^{37}$–$10^{40}$ erg over $\sim$10^4 years, which imply episodic outbursts dominate energy deposition into the ISM. No significant molecular emission is detected around MAXI J1820+070, consistent with a low-density ambient medium and a jet propagating through constant-density ISM. The results validate astrochemical calorimetry as a practical tool to constrain jet energetics in transient BHXBs and provide first constraints on formation timescales for jet–ISM interaction zones in this population.

Abstract

We present Atacama Large Millimeter/Submillimeter Array (ALMA) observations aimed at identifying potential jet-ISM interaction sites in the vicinity of the transient black hole X-ray binaries MAXI J1348-630 and MAXI J1820+070, both of which have recently undergone an outburst, and displayed powerful large scale jets. Using this dataset, we construct molecular line emission maps. By analyzing the morphological, spectral, and kinematic properties of the detected emission, we identify a molecular structure that provides compelling evidence for a jet-driven cavity in the local environment of MAXI J1348-630 but find no significant emission in the local environment of MAXI J1820+070. We use the properties of the detected molecular emission surrounding MAXI J1348-630 to constrain the jet power, finding our results to be consistent with other independent studies of this source, and further validating the utility of astrochemistry for constraining jet energetics. Additionally, our findings provide the first assessment on the formation timescales for jet-ISM interaction regions in the transient black hole X-ray binary population.

Figures (9)

• Figure 1: Left: Integrated and $4\sigma$-filtered $^{13}$CO($J=1-0$) intensity map of the MAXI J1348$-$630 field, combining ALMA 12m and ACA data. Contours are at [1.5, 2.5, 3.5] K km s$^{-1}$. Dashed cyan lines mark the radius where the ejecta decelerate; the BHXB position is shown by a red cross, and ejecta locations observed with MeerKAT and ATCA by colored crosses. The red circle indicates the synthesized beam. Right: Schematic linking the 2D emission to the 3D jet–ISM geometry: jets (orange cones), impact sites (red dots), and a possible cavity (cyan ellipsoid). The sketch is illustrative only—angles are not to scale. The ejecta slow near bright molecular emission, and the inferred cavity matches a ring-like structure.
• Figure 2: Spectral analysis of $^{13}$CO($J=1-0$) emission in the MAXI J1348$-$630 field. Left: Integrated and $4\sigma$-filtered intensity map with contours at [1.5, 2.5, 3.5] K km s$^{-1}$. The BHXB position (red cross) and approaching jet direction (red arrow) are marked. Spectral extraction regions are shown: Regions 1a–c (blue, orange, red) trace the ring feature; Region 2 (teal) samples an isolated cloud; Region 3 (green) an off-emission area. The red circle indicates the synthesized beam. Right: Corresponding spectra from the regions in the left panel. Vertical black lines mark feature centroids with uncertainties (gray bands). Regions 1a–c show a double-peaked, asymmetric profile (features A and B), consistent with a jet–ISM interaction, while additional components (C–E) likely trace unrelated molecular gas along the line of sight.
• Figure 3: Kinematic analysis of $^{13}$CO($J=1-0$) emission in the MAXI J1348$-$630 field. Left: Integrated and $4\sigma$-filtered intensity map with contours at [1.5, 2.5, 3.5] K km s$^{-1}$. The BHXB position is marked with a red cross, and the ejecta deceleration radius with a dashed cyan line. PV extraction paths are indicated: along the approaching jet (orange) and receding jet (red), both from the BHXB, and across the main ring emission (blue) from its southern end. The red circle shows the synthesized beam. Right: Position–velocity diagrams along the slices in the left panel, with contours at [0.2, 0.6, 1.0] K and the deceleration region marked by dashed cyan lines. Displaced gas is evident at the approaching/receding jet impact sites.
• Figure 4: Integrated and $4\sigma$ filtered intensity maps of $^{13}$CO($J=1-0$) molecular emission in the MAXI J1348$-$630 field over specific velocity ranges. Contours correspond to [1.05, 1.75, 2.45]K km s$^{-1}$. The cyan dashed circles represent the radius at which the ejecta decelerate, while the red cross is the position of the target BHXB. The left panel corresponds to the velocity range $v=(-54,-50)$ km s$^{-1}$ (spectral feature A, Fig. \ref{['fig:spectra']}, right) and the right panel corresponds to the velocity range $v=(-49,-45)$ km s$^{-1}$ (spectral feature B, Fig. \ref{['fig:spectra']}, right).
• Figure 5: Calorimetric life-time averaged jet power estimates for varying values of impact site ISM density ($\rho_0$) and jet opening angle ($\phi$). We show the density range constrained by the radex modelling and opening angle range below $1^\circ$. This set of results assumes $D=2.2$kpc and $i=50^\circ$. The jet power estimations range from $10^{25}-10^{28}$erg s$^{-1}$.