The ALMA Cycle 10 Proposal Process
The results of the Cycle 10 Call for Proposals were announced to the community on 21 August2023. After considering the scientific rankings and operational considerations (e.g.,
configuration schedule, available time due to weather, regional balance), 240 high-priority
programs (Grade A+B) were selected. The titles and abstracts of the selected programs areavailable on the ALMA Science Portal.
Proposals requesting less than 50 h on the 12-m Array or less than 150 h on the 7-m Array instand-alone mode were reviewed using distributed peer review, where each proposal teamnominates one person to review 10 proposals. A total of 1635 proposals went through thispeer review process, with 1098 individual reviewers. The proposals for three reviewers werecanceled by the JAO: one reviewer did not submit their Stage 1 reviews, and the JAO foundthat two other reviewers did not behave in an ethical manner.
The ALMA Proposal Review Committee (APRC) met on 10-14 July 2023 to recommend which
Large Programs should be scheduled. Large Programs were also reviewed by external ScienceAssessors, who provided their expert assessment of individual Large Programs to the APRC
but did not participate in the APRC meeting. Each external Science Assessor reviewed
between 1 and 3 Large Programs in their area of expertise and wrote a scientific assessment
for each assigned proposal. These assessments were sent to the APRC, who took thisinformation into account during the discussion of the virtual face-to-face meeting and for thecomposition of the consensus reports.
Proposal statistics and results
The community submitted a total of 1679 proposals requesting close to 29,500 h of 12-m
Array time, with an overall subscription rate on the 12-m Array of 6.9. As a result, many
excellent proposals could not be scheduled because of the high oversubscription. Table 1 andTable 2 present the selection statistics grouped by regional affiliation and scientific category,
respectively. Figures 1-3 show the time assigned to the Grade A and B proposals by region,
science category, and receiver band. Overall, 14% of the submitted proposals were acceptedwith priority Grade A or B.
Figure 4 shows the percentage of proposals assigned priority grade A or B as a function of theestimated execution time on the 12-m Array. The success rate, including Large Programs, islargely independent of execution time. The following 4 Large Programs are scheduled forCycle 10 based on the recommendation from the APRC and scheduling considerations.
1. The Large 12P COMA survey (Cometary Molecules with ALMA) (2023.1.01143.L)
PI: Martin Cordiner (NA)
2. UNveiling the Initial Conditions of the high-mass star-formation (UNIC)(2023.1.00360.L)
PI: Elena Redaelli (EU); co-PIs: Stefano Bovino (CL), Vivien Chen (EA), Patricio Sanhueza(EA), Rachel Friesen (NA)1

3. The COSMOS High-z ALMA-MIRI Population Survey (CHAMPS): A Wide-Area
Comprehensive Survey of the Dusty Universe (2023.1.00180.L)
PI: Andreas Faisst (NA); co-PIs: Jeyhan Kartaltepe (NA), Caitilin Casey (NA), Ezequiel
Treister (CL), John Silverman (EA), Manuel Aravena (CL), Jorge Zavala (EA), Sune Toft(EU).
4. Probing the molecular gas – the missing puzzle pieces to the baryon cycle(2023.1.00127.L)
PI: Celine Peroux (EU); co-PIs: Varsha Kulkarni (NA), Laurent Chemin (CL)
Table 1: Summary of submitted and accepted proposals

Chile

East Asia

Europe(CL)

(EA)

(EU)

North
America(NA)

Open Skies

Total

Submitted Proposals
Number of proposals
83
366
671
504
55
1679
12-m Array time (hours)
1508
5940
12167
9196
687
29499
7-m Array time (hours)
1299
3263
6098
5256
194
16109
Total Power Array time (hours)
792
4362
5748
4895
121
15918
Subscription rate
12-m Array (4300 h offered)
3.5
6.1
8.4
6.3
N/A
6.9
7-m Array time (4300 h offered)
3
3.4
4.2
3.6
N/A
3.7
Total Power Array (4300 h offered)
1.8
4.5
4
3.4
N/A
3.7
Grade A & B projects
Number of proposals
25627576
3240
12-m Array time (hours)
405
909
1408
1409
3241637-m Array time (hours)
212
435
592
1022
272287
Total Power Array time (hours)
202
551
834
1010
02597
Grade C projects
Number of proposals
16458456
3204
12-m Array time (hours)
219
551
856
763
1624057-m Array time (hours)
452
607
1467
575
48
3148
Total Power Array time (hours)
60
768
653
666
02148
Regional distribution of all submitted proposals, and of the proposals recommended for scheduling with Grades A and B, andGrade C. Note: subscription rates do not apply for Open Skies since all regions contribute observing time for proposals fromPIs who are not affiliated with any of the ALMA regions.

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Table 2: Proposals by science category

Category 1 Category 2 Category 3 Category 4

Category 5

Total

Submitted Proposals
Number of proposals
428
384
454
314
99
1679
12-m Array time (hours)
9272
7202
6576
5122
1326
29499
7-m Array time (hours)
1388
6015
8049
368
290
16109
Total Power Array time (hours)
395218
10487
26149
15918
Grade A & B projects
Number of proposals
6459
65
40
12240
12-m Array time (hours)
1339
1052
981
580
211
4163
7-m Array time (hours)
211
829
1134
65
48
2287
Total Power Array time (hours)
01006
1576
0152597
Grade C projects
Number of proposals
58
41
65
2416
204
12-m Array time (hours)
932
371
591
366
145
2405
7-m Array time (hours)
650
1069
1192
44
193
3148
Total Power Array time (hours)
39649
1442
1702148
Category 1: Cosmology and the high redshift universe; Category 2: Galaxies and Galactic nuclei; Category 3: Interstellar
medium, star formation, and astrochemistry; Category 4: Circumstellar disks, exoplanets, and the solar system; Category 5:
Stellar evolution and the Sun.

Figure 1: Distribution of execution time for Grade A and B projects by region for the 12-m (left), the 7-m (center), and theTotal Power (right) arrays.

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Figure 2: Distribution of execution time for Grade A and B projects by scientific category for the 12-m (left), the 7-m (center)and the Total Power (right) array.

Figure 3: Distribution of execution time for Grade A and B projects by band for the 12-m (left), the 7-m (center) and the Total
Power (right) array. Times labeled as “N/A” indicate the receiver band is not offered with that array in Cycle 10.

4Figure 4: Fraction of proposals assigned Grade A and B as a function of the estimated execution time on the 12-m Array. Theerror bars are 1 sigma from Poisson statistics.

Figure 5 (left panel) shows the mean and median time requested on the 12-m Array for GradeA+B proposals in each cycle. We can see that in Cycle 10 the typical proposal needs more than
18 h on the 12-m Array, which is a 12% increase over Cycle 9. As a result, the overall numberof accepted high-priority proposals in Cycle 10 decreased relative to Cycle 9 (see Figure 5,right panel).

Figure 5: (Left) The requested 12-m Array time per proposal that has been assigned priority Grade A or B. (Right) The numberof proposals assigned Grade A + B that requested the 12-m Array versus the proposal cycle.

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Acknowledgements
We thank the 17 members of the ALMA Proposal Review Committee (APRC) and the 73
external Science Assessors for their participation in the review process of the Large Programs.
The APRC was chaired by Dr. David Wilner, and included the following panel members:
Masayuki Akiyama
Anne Medeling
Shigehisa Takakuwa
Paolo Cassata
Yusuke Miyamoto
Ya-Wen Tang
Claudio Codella
Thushara Pillai
Tao Wang
Hiroshi Imai
Kartik ShethLin Yan
Enrique Macias
Flora Stanley
Diego Mardones
Karl Stapelfeldt
We would also like to thank the over 1000 reviewers who took part of the distributed peer
review process, whose participation was essential to the success of the Cycle 10 proposal call.

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