2014A&A...570L...9G


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.14CEST18:02:00

2014A&A...570L...9G - Astronomy and Astrophysics, volume 570, L9-9 (2014/10-1)

Constraints on photoevaporation models from (lack of) radio emission in the Corona Australis protoplanetary disks.

GALVAN-MADRID R., LIU H.B., MANARA C.F., FORBRICH J., PASCUCCI I., CARRASCO-GONZALEZ C., GODDI C., HASEGAWA Y., TAKAMI M. and TESTI L.

Abstract (from CDS):

Photoevaporation due to high-energy stellar photons is thought to be one of the main drivers of protoplanetary disk dispersal. The fully or partially ionized disk surface is expected to produce free-free continuum emission at centimeter (cm) wavelengths that can be routinely detected with interferometers such as the upgraded Very Large Array (VLA). We use deep (rms noise down to 8µJy/beam in the field of view center) 3.5cm maps of the nearby (130pc) Corona Australis (CrA) star formation (SF) region to constrain disk photoevaporation models. We find that the radio emission from disk sources in CrA is surprisingly faint. Only three out of ten sources within the field of view are detected, with flux densities of about 102µJy. However, a significant fraction of their emission is nonthermal. Typical upper limits for nondetections are 3σ∼60µJy/beam. Assuming analytic expressions for the free-free emission from extreme-UV (EUV) irradiation, we derive stringent upper limits to the ionizing photon luminosity that impinges on the disk surface ΦEUV<1-4x1041s–1. These limits constrain ΦEUV to the low end of the values needed by EUV-driven photoevaporation models to clear protoplanetary disks within the observed few Myr timescale. Therefore, at least in CrA, EUV-driven photoevaporation is unlikely to be the main agent of disk dispersal. We also compare the observed X-ray luminosities LX of disk sources with models in which photoevaporation is driven by such photons. Although predictions are less specific than for the EUV case, most of the observed fluxes (upper limits) are roughly consistent with the (scaled) predictions. Deeper observations, as well as predictions spanning a wider parameter space, are needed to properly test X-ray driven photoevaporation.

Abstract Copyright:

Journal keyword(s): protoplanetary disks - stars: formation - stars: pre-main sequence

Simbad objects: 12

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Number of rows : 12

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 SA 13- reg 10 48 +11.5           ~ 10 0
2 V* TW Hya TT* 11 01 51.9054298616 -34 42 17.031550898   11.94 10.50 10.626 9.18 K6Ve 1532 1
3 2MASS J19012872-3659317 Y*? 19 01 28.7319364964 -36 59 31.780844396         13.15 M1.0 14 0
4 2MASS J19013232-3658030 Y*O 19 01 32.3352542943 -36 58 03.475576828           M3-M4 22 0
5 2MASS J19013385-3657448 Y*O 19 01 33.859 -36 57 44.83           M2-M3 22 0
6 V* V709 CrA Or* 19 01 34.8590599569 -37 00 56.581106047   12.70 11.03     K1IV 55 0
7 HBC 677 Em* 19 01 41.6429644100 -36 59 52.869788444   17.7 16.7     M2 25 0
8 2MASS J19015112-3654122 Y*O 19 01 51.129 -36 54 12.28           M2 13 0
9 V* R CrA Ae* 19 01 53.6850227874 -36 57 08.145519972 12.781 12.651 11.917 11.242 10.412 B5IIIpe 449 1
10 2MASS J19015374-3700339 Y*O 19 01 53.7542745280 -37 00 34.072497389           M8.5 16 2
11 2MASS J19015833-3700267 Y*O 19 01 58.34 -37 00 26.8           ~ 8 0
12 V* T CrA Ae* 19 01 58.7901571143 -36 57 50.329832417     11.67     F0 155 0

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2020.07.14-18:02:00

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