Variability of Water Masers in W49N: Results from the Effelsberg - PowerPoint PPT Presentation

Variability of Water Masers in W49N: Results from the Effelsberg Long-term Monitoring Programme (2014-2017) Busaba Hutawarakorn Kramer MPIfR/NARIT Team & Collaborators Effelsberg Observations: MPIfR - Alex Kraus, Karl Menten Following up KaVA Observations (2017): Hirota (NAOJ) and Asanok (NARIT) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 1

Talk Outline Ø About W49N Ø Nearly Simultaneous Observations of the 2014 Major Outburst Ø Search for Periodic Flares during 2014-2017 Ø Effelsberg & KaVA Monitoring Observations Ø Discovery of the New Major Outburst in September 2017 & Following-up Observations with Torun Ø Summary Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 2

About W49N W49N is part of W49A - the most • luminous (> 10 7 L ¤ ) and the most massive( ~ 10 6 M ¤ ) GMC in our Galaxy (Sievers et al. 1991) Distance = 11.1 +/- 0.8 kpc (parallax • measurement, Zhang et al 2013) Well-studied since 1970 • 99% of the total flux of W49N • contained around UCHII region G Associated with H 2 O masers and • other masers (e.g. OH and methanol) De Pree et al 2000 3

VLA Observations of Water masers and UCHII Regions (De Pree et al 2000) + positive vel. Δ negative vel. 4

Nearly Simultaneous Observations of the 2014 Major Outburst Started in Early 2014 - Major high velocity flare( Peak flux ~ 80,000 Jy @ ~ -97 km/s) reported by Tolmachev in The Astronomer’s Telegram on 28 January 2014 to have occurred since September 2013 321, 325, 355, 439, 471, 475 GHz May 2014 12m APEX Chile (K. Menten, T. Kaminski) 183 GHz May 2014 30m IRAM From February 2014 Granada, Spain 22 GHz, 100-m Effelsberg (G. Xin, H. Wiesemeyer) (B. Kramer & A. Kraus) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 5

Interferometric Observations 321, 325 GHz 22 GHz SMA - May 7, 2014 VLBA – May 8, 2014 (N. Patel, T. Kaminski) (B. Zhang) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 6

22 GHz – Observations with 100m Effelsberg The extreme high velocity features up to V LSR up to -256 km/s and +271 km/s - First detected in 1975 (Morris 1976) - VLA observation (McGrath 2004) also detected them up to -352 km/s and +375 km/s Using FFT spectrometer with 65,536 channels and a bandwidth of 100 MHz centered at the systemic velocity of our sources => the spectral resolution 0.02 km/s => smoothed to 0.08 km/s 22 GHz, 28-Feb-14 100m-Effelsberg Flux Density (Jy) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 7

Submm Observations APEX 12m + IRAM 30m First detection of 475 GHz line • in SFRs Detection of both 321 and • 325 GHz lines Non detection at 354, 439, • 471 GHz Several features coincide, also • the high velocity flare features => line ratio study possible to constrain pumping models (Neufeld & Melnick 1991) 8

VLBA Map of the 2014 Outburst 40000 300 240 35000 1 . 0 180 30000 0 . 5 120 25000 North o ff set (arcsec) Flux Density (Jy) 60 0 . 0 V LSR (km s − 1 ) 20000 0 − 0 . 5 15000 − 60 − 120 10000 − 1 . 0 − 180 5000 − 1 . 5 − 240 0 − 300 − 200 − 100 0 100 200 300 − 300 1 . 5 1 . 0 0 . 5 0 . 0 − 0 . 5 − 1 . 0 LSR Velocity (km s − 1 ) East o ff set (arcsec) Observed on May 8, 2014 (Kramer et al. in prep) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 9

VLBA Observations 2010-11 BeSSeL Project ( Zhang et al. 2013 ) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 10

The location of 2014 Outburst @ -97 km/s 1 . 5 − 93 . 6 1 . 0 − 94 . 4 − 95 . 2 0 . 5 North o ff set (arcsec) − 96 . 0 V LSR (km s − 1 ) 0 . 0 − 96 . 8 − 97 . 6 − 0 . 5 − 98 . 4 − 1 . 0 − 99 . 2 − 1 . 5 − 100 . 0 2 . 0 1 . 5 1 . 0 0 . 5 0 . 0 − 0 . 5 − 1 . 0 East o ff set (arcsec) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 11

VLBA Map of the 2014 Outburst 300 300 240 0 . 4 240 1 . 0 180 180 0 . 5 120 0 . 2 120 North o ff set (arcsec) North o ff set (arcsec) 60 60 V LSR (km s − 1 ) 0 . 0 V LSR (km s − 1 ) 0 0 . 0 0 − 0 . 5 − 60 − 60 − 0 . 2 − 120 − 120 − 1 . 0 − 180 − 180 − 1 . 5 − 0 . 4 − 240 − 240 − 300 0 . 2 0 . 0 − 0 . 2 − 0 . 4 − 0 . 6 − 300 1 . 5 1 . 0 0 . 5 0 . 0 − 0 . 5 − 1 . 0 East o ff set (arcsec) East o ff set (arcsec) Observed on May 8, 2014 (Kramer et al, in prep.) Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 12

VERA Observation of the outburst in 2003 The 2003 outburst @ -30.7 km/s Honma et al 2004 Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 13

SMA – submm H 2 O Masers Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 14

SMA – submm H 2 O Masers Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 15

SMA – submm H 2 O Masers The peak of high velocity feature lies ~ 0.3” South, ~ 0.1” East of the peak of the central velocity feature Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 16

Effelsberg Monitoring after the2014 Major Outburst Awarded observing time with Effelsberg – 26 runs, every 2 weeks, full sample, 1 year period (Aug 2016-July 2017) - Kramer B., Kraus, Menten Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 17

Search for Periodic Flares Periodic & alternating flare of water masers (@22GHz) and methanol masers (@6.7 GHz) (Szymczak et al 2016) Figure 2. Selected spectra of 6.7 GHz methanol maser (red) and 22 GHz water maser (blue) of G107.298 + 5.639. Red and blue vertical bars show the methanol flux density and the water antenna temperature scales, respec- tively. The methanol profile taken on MJD 57341 has a peak of 57.7 Jy at Figure 3. Light curves of 6.7 and 22 GHz maser features which coincide − 7.43 km s − 1 not shown in the plot. in velocity within less than 1.1 km s − 1 . See Posters by Mateusz Olech and Michal Durjasz Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 18

Search for Periodic Flares ������ ���������������� ���������������� The 2014 Major Outburst ������ ���������������� ���������������� ���������������� ������ ���������������� @-97 km/s ���������������� ������ ���������������� ����������������� ������ ������ 1 . 5 ������ − 93 . 6 ������ 1 . 0 − 94 . 4 ������ − 95 . 2 0 . 5 �� North o ff set (arcsec) ���� ��� ��� ��� ��� ��� ��� ��� − 96 . 0 V LSR (km s − 1 ) ��������������� 0 . 0 − 96 . 8 ������ ��������������������������� − 97 . 6 − 0 . 5 ������ − 98 . 4 ������ − 1 . 0 − 99 . 2 ������ ����������������� − 1 . 5 − 100 . 0 2 . 0 1 . 5 1 . 0 0 . 5 0 . 0 − 0 . 5 − 1 . 0 ������ East o ff set (arcsec) ������ ������ ������ ������ �� ������ ������ ������ ������ ������ ������ ������ ������ ������ ������ ������ ���������� Effelsbeg Science Workshop 2018, Bonn, 20.02.2018 19