Water maser variability over 20 years in a large sample of star-forming regions: the complete database*
M. Felli(1), J. Brand(2), R. Cesaroni(1), C. Codella(3), G. Comoretto(1), S. Di Franco(4), F. Massi(1),
L. Moscadelli(1), R. Nesti(1), L. Olmi(3), F. Palagi(3), D. Panella(1), R. Valdettaro(1)

(1) INAF - Osservatorio Astrofisico di Arcetri
(2) INAF - Istituto di Radioastronomia

(3) INAF - Istituto di Radioastronomia, Sez. di Firenze
(4) Dipartimento di Astronomia, Università degli Studi di Firenze

* Based on observations with the Medicina radiotelescope operated by INAF - Istituto di Radioastronomia

Appears in 2007, Astronomy and Astrophysics Vol. 476, 373 - 664

The Arcetri radioastronomy group has been involved since 1987 in an observational campaign aimed at studying the variability of water masers at 22 GHz in star forming regions.  Using  the Medicina radiotelescope  (32 m), a sample of 43 star forming regions have been observed several (4-5) times per year, with a beam width ~1.9' and a typical noise (1 sigma) ~1.5 Jy.

In this paper we present a database of up to 20 years of monitoring of a sample of 43 masers within star-forming regions. The sample covers a large range of luminosities of the associated IRAS source and is representative of the entire population of water masers of this type. We give for each source:
plots of the calibrated spectra; the velocity-time-flux density plot; the light curve of the integrated flux; the lower and upper envelopes of the maser emission; the mean spectrum; the rate of maser emission as a function of velocity.
Figures for just one source are given in the text for representative purposes. Figures for all the sources are given in electronic form in the on-line appendix. Both the printed paper and the on-line material can be downloaded from this page (see below). Individual figures (including some that are not in the on-line appendix) can be downloaded for each source, using the table at the bottom of this page.

Download the printed paper (pdf; 10 pages, 866 kb) and the on-line appendix (pdf; 284 pages, 35.6Mb)

The printed version alone is also available at arXiv:0710.0790 (astro-ph)


Most of the figures are presented in the on-line appendix . In this web page we present the same figures  and  two additional  figures per source not shown in the on-line appendix. Each plot is in gzipped-postscript format and can be downloaded from the links included in this page. There are eight kinds of plots:

Fig. Ax.a: All spectra of a source with a linear-autoscaled flux density scale, determined by the maximum value found during our monitoring. Time runs from top to bottom and from left to right. In each spectrum the actual date of observation is given in the top left corner, and the number of days elapsed since the first observation of the source in the top right corner. The velocity scale is the same for all spectra.

Fig. Ax.a1: (Not shown in the on-line appendix) Same as Fig. Ax.a, but with a linear-fixed flux density scale.

Fig. Ax.a2: (Not shown in the on-line appendix) Same as Fig. Ax.a, but with a logarithmic-fixed flux density  scale, scaled to the maximum value found during the patrol.

Fig. Ax.b:  Velocity-time-flux density full plots. The vertical solid line indicates the velocity of the associated thermal molecular gas. The vertical solid line indicates the velocity of the associated thermal molecular gas. The flux density scale is shown by the bar on the right. In this bar the three lines give the flux density of the drawn contours. The area in black indicates that the corresponding velocity range was not observed.

Fig. Ax.c: Velocity-time-flux density zoomed plots. The vertical solid line indicates the velocity of the associated thermal molecular gas. The vertical dashed line marks the mean velocity derived from the histogram of the rate--of--occurrence. The flux density  scale is shown by the bar on the right. In this bar the three lines give the flux density of the drawn contours. The area in black indicates that the corresponding velocity range was not observed.

Fig. Ax.d: The integral of the flux density over the observed velocity range as a function of time.

Fig. Ax.e: The upper (red) and  lower (blue)  envelopes and the mean spectra (green) measured during our monitoring. The vertical solid line marks the velocity of the associated thermal molecular gas. The vertical dashed  line marks the mean velocity derived from the histogram of the rate-of-occurrence.

Fig. Ax.f: Rate-of-occurrence plots. The scale to the right refers to the dotted histogram, the scale to the left to the solid line histogram.  The vertical solid line marks the velocity of the associated thermal molecular gas.

All plots (gzipped-postscript files) can be downloaded from the list of sources below (coordinates are J2000).


1
NGC 281
00:52:24.7  +56:33:50
Fig A1.a
Fig  A1.a1
Fig A1.a2
Fig A1.b
Fig A1.c
Fig A1.d
Fig A1.e
Fig A1.f
2
W3 OH
02:27:04.7  +61:52:26
Fig A2.a Fig A2.a1 Fig A2.a2 Fig A2.b Fig A2.c Fig A2.d Fig A2.e Fig A2.f
3
RNO 15-FIR
03:27:38.1  +30:12:59
Fig A3.a Fig A3.a1 Fig A3.a2 Fig A3.b Fig A3.c Fig A3.d Fig A3.e Fig A3.f
4
AFGL 5142
05:30:48.0  +33:47:54
Fig A4.a Fig A4.a1 Fig A4.a2 Fig A4.b Fig A4.c Fig A4.d Fig A4.e Fig A4.f
5
Ori A-west
05:32:41.6  -05:35:47
Fig A5.a Fig A5.a1 Fig A5.a2 Fig A5.b Fig A5.c Fig A5.d Fig A5.e Fig A5.f
6
KL IRC2
05:35:14.5  -05:22:30
Fig A6.a Fig A6.a1 Fig A6.a2 Fig A6.b Fig A6.c Fig A6.d Fig A6.e Fig A6.f
7
OMC 2
05:35:27.6  -05:09:35
Fig A7.a Fig A7.a1 Fig A7.a2 Fig A7.b Fig A7.c Fig A7.d Fig A7.e Fig A7.f
8
Sh 2-231
05:39:12.9  +35:45:51
Fig A8.a Fig A8.a1 Fig A8.a2 Fig A8.b Fig A8.c Fig A8.d Fig A8.e Fig A8.f
9
HHL 26
05:40:24.1  +23:50:55
Fig A9.a Fig A9.a1 Fig A9.a2 Fig A9.b Fig A9.c Fig A9.d Fig A9.e Fig A9.f
10
Sh 2-235
05:40:53.3  +35:41:49
Fig A10.a Fig A10.a1 Fig A10.a2 Fig A10.b Fig A10.c Fig A10.d Fig A10.e Fig A10.f
11
NGC 2071
05:47:05.4  +00:21:43
Fig A11.a Fig A11.a1 Fig A11.a2 Fig A11.b Fig A11.c Fig A11.d Fig A11.e Fig A11.f
12
HH 397A
05:58:13.9  +16:32:00
Fig A12.a Fig A12.a1 Fig A12.a2 Fig A12.b Fig A12.c Fig A12.d Fig A12.e Fig A12.f
13
Mon R2 IRS3
06:07:48.0  -06:22:57
Fig A13.a Fig A13.a1 Fig A13.a2 Fig A13.b Fig A13.c Fig A13.d Fig A13.e Fig A13.f
14
Sh 2-252
06:08:35.5  +20:39:13
Fig A14.a Fig A14.a1 Fig A14.a2 Fig A14.b Fig A14.c Fig A14.d Fig A14.e Fig A14.f
15
AFGL 5180
06:08:53.3  +21:38:12
Fig A15.a Fig A15.a1 Fig A15.a2 Fig A15.b Fig A15.c Fig A15.d Fig A15.e Fig A15.f
16
GGD 12-15
06:10:52.2  -06:11:32
Fig A16.a Fig A16.a1 Fig A16.a2 Fig A16.b Fig A16.c Fig A16.d Fig A16.e Fig A16.f
17
Sh 2-255/7
06:12:53.6  +17:59:27
Fig A17.a Fig A17.a1 Fig A17.a2 Fig A17.b Fig A17.c Fig A17.d Fig A17.e Fig A17.f
18
Sh 2-269
06:14:36.5  +13:49:35
Fig A18.a Fig A18.a1 Fig A18.a2 Fig A18.b Fig A18.c Fig A18.d Fig A18.e Fig A18.f
19
NGC 2264
06:41:10.1  +09:29:22
Fig A19.a Fig A19.a1 Fig A19.a2 Fig A19.b Fig A19.c Fig A19.d Fig A19.e Fig A19.f
20
G31.41+0.31
18:47:34.7  -01:12:46
Fig A20.a Fig A20.a1 Fig A20.a2 Fig A20.b Fig A20.c Fig A20.d Fig A20.e Fig A20.f
21
W43 Main3
18:47:47.0  -01:54:35
Fig A21.a Fig A21.a1 Fig A21.a2 Fig A21.b Fig A21.c Fig A21.d Fig A21.e Fig A21.f
22
G32.74-0.08
18:51:21.9  -00:12:09
Fig A22.a Fig A22.a1 Fig A22.a2 Fig A22.b Fig A22.c Fig A22.d Fig A22.e Fig A22.f
23
G34.26+0.15
18:53:18.8  +01:14:56
Fig A23.a Fig A23.a1 Fig A23.a2 Fig A23.b Fig A23.c Fig A23.d Fig A23.e Fig A23.f
24
G35.20-0.74
18:58:12.6  +01:40:37
Fig A24.a Fig A24.a1 Fig A24.a2 Fig A24.b Fig A24.c Fig A24.d Fig A24.e Fig A24.f
25
OH43.8-0.1
19:11:54.2  +09:35:55
Fig A25.a Fig A25.a1 Fig A25.a2 Fig A25.b Fig A25.c Fig A25.d Fig A25.e Fig A25.f
26
G45.07+0.13
19:13:22.0  +10:50:52
Fig A26.a Fig A26.a1 Fig A26.a2 Fig A26.b Fig A26.c Fig A26.d Fig A26.e Fig A26.f
27
G59.78+0.06
19:43:11.5  +23:43:54
Fig A27.a Fig A27.a1 Fig A27.a2 Fig A27.b Fig A27.c Fig A27.d Fig A27.e Fig A27.f
28
ON 1
20:10:09.1  +31:31:37
Fig A28.a Fig A28.a1 Fig A28.a2 Fig A28.b Fig A28.c Fig A28.d Fig A28.e Fig A28.f
29
IRAS 20126+4104
20:14:26.0  +41:13:33
Fig A29.a Fig A29.a1 Fig A29.a2 Fig A29.b Fig A29.c Fig A29.d Fig A29.e Fig A29.f
30
AFGL 2591
20:29:24.9  +40:11:20
Fig A30.a Fig A30.a1 Fig A30.a2 Fig A30.b Fig A30.c Fig A30.d Fig A30.e Fig A30.f
31
W75-N
20:38:36.4  +42:37:35
Fig A31.a Fig A31.a1 Fig A31.a2 Fig A31.b Fig A31.c Fig A31.d Fig A31.e Fig A31.f
32
Sh 2-128(H2O)
21:32:11.4  +55:53:55
Fig A32.a Fig A32.a1 Fig A32.a2 Fig A32.b Fig A32.c Fig A32.d Fig A32.e Fig A32.f
33
AFGL 2789
21:39:58.2  +50:14:22
Fig A33.a Fig A33.a1 Fig A33.a2 Fig A33.b Fig A33.c Fig A33.d Fig A33.e Fig A33.f
34
IC1396n
21:40:41.9  +58:16:12
Fig A34.a Fig A34.a1 Fig A34.a2 Fig A34.b Fig A34.c Fig A34.d Fig A34.e Fig A34.f
35
NGC 7129 FIRS2
21:43:00.2  +66:03:26
Fig A35.a Fig A35.a1 Fig A35.a2 Fig A35.b Fig A35.c Fig A35.d Fig A35.e Fig A35.f
36
Sh 2-140 IRS1
22:19:18.3  +63:18:47
Fig A36.a Fig A36.a1 Fig A36.a2 Fig A36.b Fig A36.c Fig A36.d Fig A36.e Fig A36.f
37
L1204-G
22:21:26.7  +63:51:38
Fig A37.a Fig A37.a1 Fig A37.a2 Fig A37.b Fig A37.c Fig A37.d Fig A37.e Fig A37.f
38
IRAS 22506+5944
22:52:36.9  +60:00:48
Fig A38.a Fig A38.a1 Fig A38.a2 Fig A38.b Fig A38.c Fig A38.d Fig A38.e Fig A38.f
39
Cepheus A
22:56:18.1  +62:01:46
Fig A39.a Fig A39.a1 Fig A39.a2 Fig A39.b Fig A39.c Fig A39.d Fig A39.e Fig A39.f
40
WB89-234H2O
23:02:31.8  +56:57:44
Fig A40.a Fig A40.a1 Fig A40.a2 Fig A40.b Fig A40.c Fig A40.d Fig A40.e Fig A40.f
41
Sh 2-158
23:13:44.7  +61:28:10
Fig A41.a Fig A41.a1 Fig A41.a2 Fig A41.b Fig A41.c Fig A41.d Fig A41.e Fig A41.f
42
IRAS 23139+5939
23:16:10.3  +59:55:29
Fig A42.a Fig A42.a1 Fig A42.a2 Fig A42.b Fig A42.c Fig A42.d Fig A42.e Fig A42.f
43
IRAS 23151+5912
23:17:20.8  +59:28:47
Fig A43.a Fig A43.a1 Fig A43.a2 Fig A43.b Fig A43.c Fig A43.d Fig A43.e Fig A43.f

Last update: October 3, 2007
Please contact R. Cesaroni (INAF-Arcetri) or J. Brand (INAF-IRA)