The relationship between mid-infrared and sub-millimetre variability of deeply embedded protostars

Carlos Contreras Peña; Doug Johnstone; Giseon Baek; Gregory J. Herczeg; Steve Mairs; Aleks Scholz; Jeong-Eun Lee; The JCMT Transient Team

doi:10.1093/mnras/staa1254

The relationship between mid-infrared and sub-millimetre variability of deeply embedded protostars

Carlos Contreras Peña, Doug Johnstone, Giseon Baek, Gregory J. Herczeg, Steve Mairs, Aleks Scholz, Jeong-Eun Lee, The JCMT Transient Team

Research output: Contribution to journal › Article › peer-review

Abstract

We study the relationship between the mid-infrared (mid-IR) and sub-millimetre (sub-mm) variability of deeply embedded protostars using the multi-epoch data from the Wide-field Infrared Survey Explorer (WISE/NEOWISE) and the ongoing James Clerk Maxwell Telescope (JCMT) Transient Survey. Our search for signs of stochastic (random) and/or secular (roughly monotonic in time) variability in a sample of 59 young stellar objects (YSOs) revealed that 35 are variable in at least one of the two surveys. This variability is dominated by secular changes. Of those objects with secular variability, 14 objects (⁠22 per cent of the sample) show correlated secular variability over mid-IR and sub-mm wavelengths. Variable accretion is the likely mechanism responsible for this type of variability. Fluxes of YSOs that vary in both wavelengths follow a relation of log₁₀F_4.6(t) = ηlog₁₀F₈₅₀(t) between the mid-IR and sub-mm, with η = 5.53 ± 0.29. This relationship arises from the fact that sub-mm fluxes respond to the dust temperature in the larger envelope whereas the mid-IR emissivity is more directly proportional to the accretion luminosity. The exact scaling relation, however, depends on the structure of the envelope, the importance of viscous heating in the disc, and dust opacity laws.

Original language	English
Pages (from-to)	3614–3635
Journal	Monthly Notices of the Royal Astronomical Society
Volume	495
Issue number	4
Early online date	11 May 2020
DOIs	https://doi.org/10.1093/mnras/staa1254
Publication status	Published - Jul 2020

Keywords

Stars: formation
Stars: pre-main-sequence
Stars: protostars
Stars: variables: T Tauri
Herbig Ae/Be
Infrared: stars
Submillimetre: stars

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10.1093/mnras/staa1254

Peña-2020-Relationship-between-mid-infra-MNRAS-3614
Copyright © 2020 the Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.1093/mnras/staa1254.
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http://adsabs.harvard.edu/abs/2020MNRAS.tmp.1415C

Astronomy at St Andrews 2018-2021: Astronomy at St Andrews 2018-2021
Jardine, M. M. (PI), Bonnell, I. A. (CoI), Cameron, A. C. (CoI), Cyganowski, C. J. (CoI), Dominik, M. (CoI), Helling, C. (CoI), Horne, K. D. (CoI), Scholz, A. (CoI), Tojeiro, R. (CoI), Weijmans, A.-M. (CoI), Wild, V. (CoI), Woitke, P. (CoI), Wood, K. (CoI) & Zhao, H. (CoI)
1/04/18 → 31/03/22
Project: Standard

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@article{bb5f6b47cadd4d6cab7840d4c5e9d490,

title = "The relationship between mid-infrared and sub-millimetre variability of deeply embedded protostars",

abstract = "We study the relationship between the mid-infrared (mid-IR) and sub-millimetre (sub-mm) variability of deeply embedded protostars using the multi-epoch data from the Wide-field Infrared Survey Explorer (WISE/NEOWISE) and the ongoing James Clerk Maxwell Telescope (JCMT) Transient Survey. Our search for signs of stochastic (random) and/or secular (roughly monotonic in time) variability in a sample of 59 young stellar objects (YSOs) revealed that 35 are variable in at least one of the two surveys. This variability is dominated by secular changes. Of those objects with secular variability, 14 objects (⁠22 per cent of the sample) show correlated secular variability over mid-IR and sub-mm wavelengths. Variable accretion is the likely mechanism responsible for this type of variability. Fluxes of YSOs that vary in both wavelengths follow a relation of log10F4.6(t) = ηlog10F850(t) between the mid-IR and sub-mm, with η = 5.53 ± 0.29. This relationship arises from the fact that sub-mm fluxes respond to the dust temperature in the larger envelope whereas the mid-IR emissivity is more directly proportional to the accretion luminosity. The exact scaling relation, however, depends on the structure of the envelope, the importance of viscous heating in the disc, and dust opacity laws.",

keywords = "Stars: formation, Stars: pre-main-sequence, Stars: protostars, Stars: variables: T Tauri, Herbig Ae/Be, Infrared: stars, Submillimetre: stars",

author = "{Contreras Pe{\~n}a}, Carlos and Doug Johnstone and Giseon Baek and Herczeg, {Gregory J.} and Steve Mairs and Aleks Scholz and Jeong-Eun Lee and {The JCMT Transient Team}",

note = "Funding: The contribution of CCP was funded by a Leverhulme Trust Research Project Grant. AS is supported by the STFC grant no. ST/R000824/1. GJH is supported by general grant 11773002 awarded by the National Science Foundation of China. DJ is supported by NRC Canada and by an NSERC Discovery Grant. J-EL and GB are supported by the Basic Science Research Program through the National Research Foundation of Korea (grant no. NRF-2018R1A2B6003423) and the Korea Astronomy and Space Science Institute under the R&D program supervised by the Ministry of Science, ICT and Future Planning. G.B. was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (NRF-2017H1A2A1043046-Global Ph.D.Fellowship Program).",

year = "2020",

month = jul,

doi = "10.1093/mnras/staa1254",

language = "English",

volume = "495",

pages = "3614–3635",

journal = "Monthly Notices of the Royal Astronomical Society",

issn = "0035-8711",

publisher = "Oxford University Press",

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TY - JOUR

T1 - The relationship between mid-infrared and sub-millimetre variability of deeply embedded protostars

AU - Contreras Peña, Carlos

AU - Johnstone, Doug

AU - Baek, Giseon

AU - Herczeg, Gregory J.

AU - Mairs, Steve

AU - Scholz, Aleks

AU - Lee, Jeong-Eun

AU - The JCMT Transient Team

N1 - Funding: The contribution of CCP was funded by a Leverhulme Trust Research Project Grant. AS is supported by the STFC grant no. ST/R000824/1. GJH is supported by general grant 11773002 awarded by the National Science Foundation of China. DJ is supported by NRC Canada and by an NSERC Discovery Grant. J-EL and GB are supported by the Basic Science Research Program through the National Research Foundation of Korea (grant no. NRF-2018R1A2B6003423) and the Korea Astronomy and Space Science Institute under the R&D program supervised by the Ministry of Science, ICT and Future Planning. G.B. was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (NRF-2017H1A2A1043046-Global Ph.D.Fellowship Program).

PY - 2020/7

Y1 - 2020/7

N2 - We study the relationship between the mid-infrared (mid-IR) and sub-millimetre (sub-mm) variability of deeply embedded protostars using the multi-epoch data from the Wide-field Infrared Survey Explorer (WISE/NEOWISE) and the ongoing James Clerk Maxwell Telescope (JCMT) Transient Survey. Our search for signs of stochastic (random) and/or secular (roughly monotonic in time) variability in a sample of 59 young stellar objects (YSOs) revealed that 35 are variable in at least one of the two surveys. This variability is dominated by secular changes. Of those objects with secular variability, 14 objects (⁠22 per cent of the sample) show correlated secular variability over mid-IR and sub-mm wavelengths. Variable accretion is the likely mechanism responsible for this type of variability. Fluxes of YSOs that vary in both wavelengths follow a relation of log10F4.6(t) = ηlog10F850(t) between the mid-IR and sub-mm, with η = 5.53 ± 0.29. This relationship arises from the fact that sub-mm fluxes respond to the dust temperature in the larger envelope whereas the mid-IR emissivity is more directly proportional to the accretion luminosity. The exact scaling relation, however, depends on the structure of the envelope, the importance of viscous heating in the disc, and dust opacity laws.

AB - We study the relationship between the mid-infrared (mid-IR) and sub-millimetre (sub-mm) variability of deeply embedded protostars using the multi-epoch data from the Wide-field Infrared Survey Explorer (WISE/NEOWISE) and the ongoing James Clerk Maxwell Telescope (JCMT) Transient Survey. Our search for signs of stochastic (random) and/or secular (roughly monotonic in time) variability in a sample of 59 young stellar objects (YSOs) revealed that 35 are variable in at least one of the two surveys. This variability is dominated by secular changes. Of those objects with secular variability, 14 objects (⁠22 per cent of the sample) show correlated secular variability over mid-IR and sub-mm wavelengths. Variable accretion is the likely mechanism responsible for this type of variability. Fluxes of YSOs that vary in both wavelengths follow a relation of log10F4.6(t) = ηlog10F850(t) between the mid-IR and sub-mm, with η = 5.53 ± 0.29. This relationship arises from the fact that sub-mm fluxes respond to the dust temperature in the larger envelope whereas the mid-IR emissivity is more directly proportional to the accretion luminosity. The exact scaling relation, however, depends on the structure of the envelope, the importance of viscous heating in the disc, and dust opacity laws.

KW - Stars: formation

KW - Stars: pre-main-sequence

KW - Stars: protostars

KW - Stars: variables: T Tauri

KW - Herbig Ae/Be

KW - Infrared: stars

KW - Submillimetre: stars

U2 - 10.1093/mnras/staa1254

DO - 10.1093/mnras/staa1254

M3 - Article

SN - 0035-8711

VL - 495

SP - 3614

EP - 3635

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 4

ER -

The relationship between mid-infrared and sub-millimetre variability of deeply embedded protostars

Abstract

Keywords

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Projects

Astronomy at St Andrews 2018-2021: Astronomy at St Andrews 2018-2021

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