相关论文: Analyzing JWST/NIRSpec Hydrogen Line Detections at…

Advances in high-resolution imaging have revealed H$\alpha$ emission separated from the host star. It is generally believed that the emission is associated with forming planets in protoplanetary disks. However, the nature of this emission…

Stars form by accreting material from their surrounding disks. There is a consensus that matter flowing through the disk is channelled onto the stellar surface by the stellar magnetic field. This is thought to be strong enough to truncate…

Emission lines indicative of active accretion have been seen on a handful of low-mass companions (M < 30 MJup) to stars. Line variability is ubiquitous on stellar accretors but has never been characterized in detail on low-mass companions…

We present a near-infrared direct imaging search for accretion signatures of possible protoplanets around the young stellar object (YSO) TW Hya, a multi-ring disk exhibiting evidence of planet formation. The Pa$\beta$ line (1.282 $\mu$m) is…

Accretion among planets is a poorly understood phenomenon, due to lack of both observational and theoretical studies. Detection of emission lines from accreting gas giants facilitate detailed investigations into this process. This work…

Accreting planets have been seen at Ha (H alpha), but targeted searches have not been fruitful. For planets, accretion tracers should come from the shock itself, exposing them to extinction by the accreting material. High-resolution (R>5e4)…

We present two epochs of observations of TW Hya from the high-dispersion near-IR spectrograph ARIES at the MMT. We detect strong emission from the Brackett gamma transition of hydrogen, indicating an accretion rate substantially larger than…

Accretion and ejection sets the outcome of the star and planet formation process. The mid-infrared wavelength range offers key tracers of those processes that were difficult to detect and spatially resolve in protostars until now. We aim to…

Using HST-COS FUV spectra, we have discovered warm molecular hydrogen in the TWA 7 system. TWA 7, a $\sim$9 Myr old M2.5 star, has a cold debris disk and has previously shown no signs of accretion. Molecular hydrogen is expected to be…

Measurements of accretion rates onto planetary mass objects may distinguish between different planet formation mechanisms, which predict different accretion histories. In this Letter, we use \HST/WFC3 UVIS optical photometry to measure…

Accretion signatures from bound brown dwarf and protoplanetary companions provide evidence for ongoing planet formation, and accreting substellar objects have enabled new avenues to study the astrophysical mechanisms controlling formation…

Accretion processes in the planetary-mass regime remain poorly constrained, yet they strongly influence planet formation, evolution, and the composition of circumplanetary disks (CPDs). We investigate the resolved Balmer hydrogen…

Recent observations have detected excess H$\alpha$ emission from young stellar systems with an age of several Myr such as PDS 70. One-dimensional radiation-hydrodynamic models of shock-heated flows that we developed previously demonstrate…

We present 1-5um spectroscopy of the young planetary mass companion TWA 27B (2M1207B) performed with NIRSpec on board the James Webb Space Telescope. In these data, the fundamental band of CH_4 is absent and the fundamental band of CO is…

The Paschen beta (1.2822 micron) emission line found in the near-infrared spectra of T-Tauri stars (TTSs) is believed to trace the accretion of material onto the central star. We present spectroscopic data which suggests that this may not…

We present a comprehensive study of mid-infrared neutral hydrogen (H~\textsc{i}) emission lines in 79 nearby (d $<$ 200 $pc$) young stars using JWST/MIRI. We aim to identify mid-infrared H~\textsc{i} transitions that can serve as reliable…

In this paper, we establish and calibrate mid-infrared hydrogen recombination lines observed with JWST as accretion tracers for pre-main-sequence stars that accrete from circumstellar disks. This work is part of a coordinated,…

Accreting planets have been detected through their hydrogen-line emission, specifically H$\alpha$. To interpret this, stellar-regime empirical correlations between the H$\alpha$ luminosity $L_\mathrm{H\alpha}$ and the accretion luminosity…

With a mass in the Neptune regime and a radius of Jupiter, WASP-107b presents a challenge to planet formation theories. Meanwhile, the planet's low surface gravity and the star's brightness also make it one of the most favorable targets for…

We report the first near-infrared detection of the bipolar microjet from TTauri star ThA 15-28 (aka Th 28). Spectra were obtained with VLT/ISAAC for the slit both perpendicular and parallel to the flow to examine jet kinematics and gas…